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Model 1005

1. If you select TRIGGER SOURCE A defaut acquisitions start when the signal on INPUT A fulfills the selected trigger conditions If you select TRIGGER SOURCE TRIG the previous rule is valid for the signal on the TRIGGER input TRIGGER LEVEL This function allows you to set the level that the signal must cross to trigger acquisitions Normally after you enter SINGLE or DUAL INPUT SCOPE mode the AUTO RANGE function automatically sets and maintains an optimal trigger level as the signal changes Move the trigger level icon or icon to the desired level by using A and W keys HORIZONTAL TRIGGER POSITION HORIZ TRIG POS You can use the INSTRUMENT SETUP menu to set the Horizontal Trigger Position Horiz Trig Pos to three different horizontal locations on the display depending on whether you want to see conditions that led up to the trigger event or those following it e 10 Trigger located close to left edge of display 50 Trigger located at center display 90 Trigger located close to right edge of display Use 10 Trigger to show events which happen after the trigger Use 90 Trigger to show events leading up to the trigger Noise Filter Function There are cases where you may want to filter out noises in order to see a better signal This can be especially true when ignition noise is present The instrument provides a noise filter for each input channel which reduces the bandwidth from its nomal 5 MHz to 2 KHz You ca
2. This instrument offers the following features A 25 Mega sample Second one channel minimum sample rate for rapid data updates Lab scope signal patterns True RMS Graphing Multimeter GMM measurements and graphs A unique Glitch Snare mode which captures displays and optionally saves abnormal signal patterns in the Scope mode of the COMPONENT TESTS only when they occur Preset tests that enable the user to check the majority of automotive sensors actuators and systems easily and quickly Powerful builtin reference information for each preset test which includes a test procedure showing how to connect to the circuit a normal reference signal pattern theory of operation and troubleshooting tips Menu driven interface has automatic configurations for most of non preset tests so you will find that the instrument is easy to use The Secondary Ignition Single function displays the waveform along with the spark voltage RPM burn time and burn voltage The Diesel function allows you to set injection pump timing and RPM using the optional Diesel accessories USB interface supports updates for code and data Even though this instrument is designed to configure itself to almost any test it is very important that you continue through this manual and carefully read and understand the capabilities of this instrument before attempting actual measurements 4 2 QUICK TOUR Powering the Instrument Press the POWER key to turn the instrum
3. USER LAST SETUP OFF CONTRAST 4 GRATICULE ON HORIZ TRIG POS 10 ACQUIRE MODE PEAK DETECT SENSOR TESTS MENU ABS Sensor Mag O2S Sensor Zirc Dual O2 Sensor ECT Sensor Fuel Temp Sensor IAT Sensor Knock Sensor TPS Sensor CKP Magnetic CKP Hall CKP Optical CMP Magnetic CMP Hall CMP Optical VSS Magnetic VSS Optical MAP Analog MAP Digital MAF Analog MAF Digi Slow MAF Digi Fast MAF Karman Vrtx EGR DPFE ACTUATOR TESTS MENU Injector PFI MFI Injector TBI Injector PNP Injector Bosch Mixture Cntl Sol EGR Cntl Sol IAC Motor IAC Solenoid Trans Shift Sol Turbo Boost Sol Diesel Glow Plug ELECTRICAL TESTS MENU Power Circuit V Ref Circuit Ground Circuit Alternator Output AUTO POWER OFF MENU AUTO POWER OFF ON AUTO POWER OFF TIME 30 min Alternator Field VR Alternator Diode Audio System DC Switch Circuits LANGUAGE MENU LANGUAGE ENGLISH IGNITION TESTS MENU PIP SPOUT DI Primary i DIESEL MENU DI Secondary DIESEL INJECTOR DIS Primary ADVANCE DIS Secondary G 6
4. eee MAKE BMW MODEL 5251 ENGINE 2 5L FUELSYS Multiport Fuel Injection een es pentanans eam rey all A PCM_PIN 22 WhtGrn wire Y n a5 t Sal h fS STATUS KOER Key On Running E LA ETEA a oa Idle a ENG_TMP Operating Temperature VACUUM 15 In Hg Auto XY BOY Sms MILEAGE 72822 The idle control output command from the PCM should change when accessories are switched on and off or the transmission is switched in and out of gear The pulse width modulated signals from the PCM should control the speed of the motor and in turn the amount of air bypassing the throttle plate The turn off spikes may not be present in all IAC drive circuits IMPORTANT Before diagnosing IAC motor several things must be checked and verified the throttle plate should be free of carbon buildup and should open and close freely the minimum air rate minimum throttle opening should be set according to manufacturer s specifications and check for vacuum leaks or false air leaks Troubleshooting Tips If the engine idle speed doesn t change corresponding with the change of the PCM s command signal suspect a bad IAC motor or clogged bypass passage IAC Idle Air Control Solenoid e Theory of Operation Idle air control solenoids keep the engine idling as low as possible without stalling and as smoothly as possible when accessories such as air conditioning compressors alternators and power steering load the eng
5. ENGINE 5 0L FUELSYS Multiport Fuel Injection PCM_PIN 58 Tan wire STATUS KOER Key On Running 20 PCM turns circuit on here RPM Idle ENG_TMP Operating Temperature i circuit off here VACUUM 191n Hg saN na S AAN ms MILEAGE 66748 When the Feedback Fuel Control System controls fuel mixture properly the injector on time will modulate from about 1 6 ms at idle to about 6 35 ms under cold cranking or Wide Open Throttle WOT operation The injector coil release spike s ranges are from 30 V to 100 V normally Troubleshooting Tips Spikes during on time or unusual high turn off spikes indicate the injector driver s malfunction Peak and Hold Type TBI Injector e Theory of Operation Peak and Hold fuel injector drivers are used almost exclusively on Throttle Body Injection TBI systems These drivers are only used on a few selected MFI systems like GM s 2 3 L Quad 4 engine family Saturn 1 9 L and Isuzu 1 6 L The driver is designed to allow approximately 4 A to flow through the injector coil and then reduce the current flow to a maximum of about 1 A Generally far more current is required to open the pintle valve than to hold it open The PCM continues to ground the circuit hold it at 0 V until it detects about 4 A flowing through the injector coil When the 4 A Peak is reached the PCM cuts back the current to a maximum of 1 A by switching in a current limiting resistor This reduction in c
6. a world leader in test amp measurement FINEST l FINE INSTRUMENTS CORPORATION 341 5 SONGNAE DONG SOSA GU BUCHON SHI KYUNGGI DO KOREA TEL 82 32 668 6042 FAX 82 32 656 5844 E mail fine finest co kr Copyright 2004 Fine Instruments Corp All right reserved Specifications subject to change without notice Litho in Korea FINEST Model 1005 Automotive Scope GMM User s Manual FINE INSTRUMENTS CORPORATION jib DANGER When handling any signals higher than 150 V peak don t electrically activate BOTH CH A and or CH B terminal s AND USB terminal together at a time If they are electrically activated simultaneously a death or a serious personal injury could be resulted in ib CAUTION When handing any extremely high voltage signals e g the signals generated from the spark plugs NEVER PUT ANY TEST LEADS Either the Red or Yellow test leads Or the Secondary ignition probe lead Or Power Cable from Cigarette Lighter CONNECTED TO THE SCOPE IN THE AREAS NEAR THOSE STRONG SIGNALS If so the scope can be damaged or worked improperly Menu Overview MAIN MENU COMPONENT TESTS SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP GRAPHING MULTIMETER MENU VOLT DC AC OHM DIODE CONTINUITY RPM FREQUENCY DUTY CYCLE PULSE WIDTH DWELL IGNITION PEAK VOLTS IGNITION BURN VOLTS IGNITION BURN TIME INJECTOR PEAK VOLTS INJECTOR ON TIME AMP DC AC TEMPERATUR
7. and low output voltage a Lean condition A titania type O2 sensor changes resistance as the oxygen content of the fuel mixture changes This results in a low output voltage from a Rich condition and a high output voltage from a Lean condition Most Titania O2 sensors are found on MFI Multiport Fuel Injection systems A voltage swing between 100 mV and 900 mV indicates that the O2 sensor is properly signalling PCM to control the fuel mixture Symptoms OBD II DTC s P0130 P0147 P0150 P0167 Feedback Fuel Control System s FFCS s no entering Closed Loop operation high emissions poor fuel economy Test Procedure 1 Connect the shielded test lead to the CH A input and connect the ground lead of the test lead to the sensor output LO or GND and the test lead probe to the sensor output or HI Get the color of the O2 signal wire or PCM pin number from a wiring diagram 2 Warm the engine and O2 sensor for 2 3 minutes at 2500 RPM and let the engine idle for 20 seconds 3 Rev the engine rapidly five or six times in 2 second intervals from idle to Wide Open Throttle WOT Be careful not to overrev the engine Engine RPM over about 4000 is not necessary Just get good snap throttle accels and full decels 4 Use the HOLD key to freeze the waveform on the display to check the maximum O2 voltage minimum O2 voltage and response time from Rich to Lean Reference Waveform VEHICLE INFORMATION Example of good O2 wa
8. even the narrowest glitches The SINGLE INPUT SCOPE mode Component Tests only provides for the display of up to four meter measurements above the waveform viewing area 4 8 GMM GRAPHING MULTIMETER MODE 9 GMM mode plots the results of signal measurements such id as frequency as the values change with time The time l range in GMM mode may be set manually from 5 seconds to 24 hours per display NOW 723mV HOLD x MAX 895 mV MIN 102 mV GMM Ranges for the vertical scale may also be set manually and the available range depends upon the measurement being displayed Where possible measurements plotted in GMM mode are performed on a cycle by cycle basis resulting in extremely fast response This mode is very suitable to find faults in slowly changing processes Figure 10 GMM Mode Indicators Indicate meter measurement functions NOW Most recent meter reading MAX Maximum value since last reset MIN Minimum value since last reset Indicate HOLD function enabled Low battery indicator Indicate GMM mode Indicate AUTORANGING mode Pressing sro sets automatic ranging on Using the Four Way arrow keys for ranging turns automatic ranging off and extinguishes AUTO Indicate voltage per division Indicate time per display Indicate signal source channel aeo s Cae 5 INSTRUMENT OPERATION 5 1 INSTRUMENT TEST MODES From the MAIN MENU you can choose 3 independent instrument test modes e CO
9. s can be set 6 21 Symptoms OBD II DTC s P0500 P0503 Improper transmission shifting inaccurate speedometer problems affecting ABS and cruise control Test Procedure 1 Raise the drive wheels off the ground and place the transmission in drive 2 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 3 With KOBD Key On Being Driven monitor the VSS output signal at low speed about 30 MPH while gradually increasing the speed of the drive wheels 4 Use the Glitch Snare mode the detect spikes and dropouts Reference Waveform VEHICLE INFORMATIONS FREQ 19 2 Hz MAX 12 0 V Frequency Modulated Signal YEAR 1984 MIN 0 00 V Frequency increases with MAKE Oldsmobile vehicle speed MODEL Toronado f ENGINE 5 0L TE Pp en pe PY a Af FUELSYS Feedback Carburetor Hy PCM_PIN 16 Brn wire iy if UE IE STATUS KOBD Key On Being Driven wait dL RPM 1350 i ENG_TMP Operating Temperature i VACUUM 15 In Hg 5V Auto f 40V 50 ms MILEAGE 52624 The signal frequency should increase with increasing vehicle speed but the duty cycle should stay consistent at any speed The amplitude frequency and shape should be all consistent in the waveform from pulse to pulse The amplitude should be sufficient usually equal to sensor supply voltage the time between pulses repeatable and the shapes repeatable and predictable Troubleshooting
10. 1 to Memory 4 By setting the Auto Save option you can automatically fill up all four memories with the four most recent unusual events Best of all Glitch Snare operation is completely automatic Trigger thresholds are calculated automatically based on recent signal history The measurement used as a basis for Glitch Snare operation is Period by default Certain COMPONENT TESTS use other measurements and some tests disable Glitch Snare when it is inappropriate Glitch Snare is most useful with continuous AC or digital signals where the information is embedded in the signalis frequency pulse width or duty factor To enable Glitch Snare operation press the Glitch Snare function key in the Scope mode of the COMPONENT TESTS If Glitch Snare is available for the current test the instrument will display the Glitch Snare display in a line along with a conventional scope display in a solid line for comparison Vertical and horizontal settings for both displays are matched For example COMPONENT TESTS ACTUATORS INJECTOR PFI MFI ACTUATOR INJECTOR PFI MFI SACK aa GLITCH lt KEYS SNARE CG CED ED CF i ACTUATOR INJECTOR PFI MFI BACK AUTO SAVE S KEYS D CF3 G 5 8 TIPS FOR NOISE MANAGEMENT The instrument is very sensitive to spikes and other noise pulses which may be present on automotive signals While this capability can be valuable when tracking down glitch related problems it can also obscure the signal you r
11. 5 In Hg i Auo X gov 20m3 MILEAGE 104402 When the main venturi metering circuits are adjusted properly lean stop air bleed etc the mixture control signal should oscilate around 50 duty cycle normally When the main metering and idle mixture adjustments are set correctly the tall spike will oscillate slightly from right to left and back again but remain very close to the middle of the two vertical drops in the waveform The PCM is oscillating the signal right to left based on input from the O2 sensor Troubleshooting Tips If the duty cycle does not remain around 50 check for vacuum leaks or a poor mixture adjustment If the waveform oscillates around 50 duty cycle during one operating mode for instance idle but not another then check for vacuum leaks misadjusted idle mixture main metering mixture or other non feedback system problems that affect mixture at different engine speeds EGR Exhaust Gas Recirculation Control Solenoid e Theory of Operation EGR systems are designed to dilute the air fuel mixture and limit NOx formation when combustion temperatures generally exceed 2500 F 1371 C and air fuel ratios are lean The effect of mixing exhaust gas a relatively inert gas with the incoming air fuel mixture is a sort of chemical buffering or cooling of the air and fuel molecules in the combustion chamber This prevents excessively rapid burning of the air fuel charge or even detonation both of which can
12. CA113 OS AT Optional 1 ea Diesel Probe Set Optional 1ea Temperature Probe Optional 1ea Isolated 12V Charging Adaptor Optional 1 ea Isolated 24V Charging Adaptor Optional 1 ea Scope Specifications Trigger Trigger Source CHA CH B TRIGGER External trigger Sensitivity CH A lt 1 0 div to 5 MHz Sensitivity Trigger 0 2 V p p Modes Single shot Normal Auto Coupling AC DC Slope Rising and falling edge Others Glitch Snare SCOPE Mode Component test only Acquire Mode SCOPE Mode Setup memory 8 Waveform amp Setup Reference waveform 51 Waveform and Setup Horizontal Sample rate 25 Mega sample second Record length 1000 Points Update rate Real time Roll Accuracy 0 1 1 pixel Sweep rate 1 us to 50 sec in a 1 2 5 sequence Scope mode 5 s to 24 Hours in a 1 2 5 sequence GMM mode Vertical Band width DC to 5 MHz 3 dB Resolution 8 bit Channel 2 Channel Coupling AC DC GND Input Impedance 1 Mohm 70 pF Maximum Input Voltage 300 V Volt Division 50 mV to 100 V in a 1 2 5 sequence Accuracy 3 Cursor Time and Volt Instrument Setup Graphing Multimeter GMM Specifications Language Contrast Graticule DC Voltage Measurement Range Accuracy 500 mV 0 001 V 0 01 V 600 v gt Input Impedance 10 MQ 0 3 5 d AC Voltage Measurement Accuracy 40 Hz 400 Hz 400 Hz 10 kHz Range R
13. COMPONENT TESTS only To change from Scope test mode to GMM test mode press the function key This Label is displayed in the GMM test mode of the COMPONENT TESTS only To change from GMM test mode to Scope test mode press the function key This Label is displayed in the Scope test of the COMPONENT TESTS only To capture display and optionally save abnormal signal patterns when they occur press the function key 4 7 SCOPE MODE FIRE 11 3kV RPM 1180 DUR 1 29 ms BURN 1 00 kV Figure 9 Scope Mode Indicators Indicate meter measurement function Indicate HOLD function enabled Backlit indicator Low battery indicator Indicate SCOPE mode Indicate AUTORANGING mode Indicate FILTER function enabled Indicate time base per division Indicate trigger level voltage Blank if DC if AC Indicate trigger slope rising or falling Indicate AUTO triggered Blank if DC if AC if GND Indicate signal source channel Indicate INPUT A zero level Indicate trigger location Indicate voltage per division and coupling SCOPE mode provides a display of signal patterns from either CH A or CH B over times ranging from 1 us to 50 seconds per division and for voltage ranges from 50 mV to 300 V full scale The display may be triggered at all time settings and trigger slope and level may be adjusted as needed The scope display is defaulted in Glitch Detect mode to display
14. a straight line at the system voltage and drops to ground when the PCM activates the solenoid A power feed controlled solenoid on a DC switched circuit appears as a straight line at 0 V until the PCM activates the solenoid Many vehicle PCM s are programmed not to enable TCC operation until the engine reaches a certain temperature as well as a certain speed 6 44 Symptoms Slow and improper shifting engine stops running when vehicle comes to a stop e Test Procedure 1 Connect the CH A lead to the transmission shift solenoid control signal from the PCM and its ground lead to the chassis GND 2 Drive the vehicle as needed to make the driveability problem occur or to exercise the suspected shift solenoid circuit 3 Make sure that the amplitude is correct for the suspected transmission operation 4 Use the proper transmission fluid pressure gauges to make sure the transmission fluid pressure and flow being controlled by the solenoid is being effected properly by solenoid operation This will help discriminate between an electronic problem and a mechanical problem such as a sticking solenoid valve clogged fluid passages or leaking internal seals etc in the transmission e Reference Waveform VEHICLE INFORMATIONS Vehicle speed reached YEAR 1993 35 MPH here and PCM MAKE Ford turned shift solenoid on MODEL Explorer peer crm a ENGINE 4 0L 10v 144 PF FUELSYS Multiport Fuel Injection PCM_PIN 52 Org Yel wire
15. acceleration not only does the sensor s frequency output increases but also its pulse width changes 6 29 Symptoms OBD II DTC s P0100 P0104 Hesitation stall low power idle problems excessive fuel consumption emissions failure e Test Procedure 1 Connect the CH A lead to the sensor output HI and its ground lead to the sensor output LO or GND 2 With the Key On Engine Running KOER use the throttle to accelerate and decelerate the engine Try different RPM ranges while spending more time in the RPM ranges that correspond to the driveability problem 3 Make sure that the amplitude frequency shape and pulse width are all consistent repeatable and accurate for any given operating mode 4 Make sure that the sensor generates the correct and steady frequency for a given RPM or airflow rate 5 Use the Glitch Snare mode to detect dropouts or unstable output frequency e Reference Waveform VEHICLE INFORMATIONS FREQ 69 4 Hz avg F MAX 5 06 V 1 i YEAR 1992 a MIN 933 mV MAKE Mitsubishi Karman Vortex MAF sensor MODEL Eclipse during snap acceleration ENGINE 1 8L a ii it MI Ni FUELSYS Multiport Fuel Injection l ii Al IH imi PCM_PIN 10 GrnBlu wire OREU La TUR NUE A STATUS KOER Key On Running w RPM Snap Acceleration S i i ENG_TMP Operating Temperature VACUUM 3 24 In Hg 2y Sse cee MILEAGE 49604 Frequency increases as airflow rate increases Pulse width duty cycle is mod
16. all ignition wires and components whenever possible e Use the shortest test leads possible since other test leads may act as an antenna and increase the potential for interference especially at higher frequency levels that are found when probing near the vehiclejs on board computer e With the potential for RF interference in the engine compartment if possible use the vehicle chassis as ground when connecting the oscilloscope test leads In some cases the engine block can actually act as an antenna for the RF signals e The test leads are a very important part of any oscilloscope Substituting other leads in both length and capability may alter the signals on your display m The oscilloscope can also pick up interference like the test leads e Because the oscilloscope circuits are so sensitive and therefore powerful do not place the oscilloscope directly on ignition wires or near high energy ignition components like coil packs e If you are using the AC or DC charger adaptor to power the oscilloscope keep the external power leads far away from the engine and ignition if possible 3 3 4 GETTING STARTED 4 1 PRODUCT DESCRIPTION This instrument is a battery operated 2 channel lab scope advanced true rms graphing multimeter GMM designed expressly for use in the automotive service market The main purpose of this instrument is to provide advanced troubleshooting capabilities for automotive service technicians in an easy to operate format
17. assure a good contact of the fuel line itself to the Piezo Pickup and ground clip Use sandpaper preferably a de greaser to clean the lines Positioning and Probe Connection The Piezo Adapter should be placed as dose as possible to the Diesel injector on a straight part of the fuel line Clamp the ground clip close to the Piezo Pickup Make sure that the ground clip does not make contact to the piezo itself or to adjacent fuel lines Connect the adapter to the instrument Notice that the ground wire is shorter than the signal wire in order to have the weight of probe and cable loaded on the ground wire not on the signal wire The piezo element may not bounce or rattle on the fuel line or make contact to other fuel lines or any other material close by 6 68 Some tips to keep in mind Always position the piezo pickup on the fuel line at about the same distance from the injector e Place the pickup on a straight part of the fuel line Don t place it on a bent part of the line e Always compare results with a reference waveform from a good diesel engine to get acquainted with the signal shape e Always compare signals at the same engine speed RPM e Pump timing is critical and should occur within 1 degree of crankshaft rotation Diesel Injector Diesel RPM Measurement and Diesel Injection Pattern Display Use the optional Diesel Probe Set consisting of a Piezo Pickup which is clamped on the diesel fuel pipe and a Diesel Adaptor t
18. down for both channels CH A amp CH B Ranges Time Bass up and down for both channels CH A amp CH B ITEM KEYS DESCRIPTION Sets automatic ranging on and off toggle When on the top right display shows AUTO When this function is set on it searches for the best range and time base settings and once found it tracks the signal When this function is off you should manually control ranging uGHT Turns the LCD Backlight on and off Conan Turns the power on and off toggle When you turn the power on previous settings are activated cunsoa Allows you to use cursors for measurements on waveforms A cursor is a vertical line or a horizontal line that you can move over the waveform like a ruler to measure values at specific points Freezes the display HOLD is displayed at the top right Also displays a menu to save or recall screens or to clear the memory Y COM TRIGGER A300V 5Y A30V 5Y ALL INPUTS 300V CAT II Figure 5 Measurement Connections INPUT A Red INPUT A is used for all single channel measurements sometimes combined with use of the other inputs Various test leads and adapters are required depending on the type of measurement selected INPUT B Yellow INPUT B is used in conjunction with INPUT A In COMPONENT TEST mode for DUAL O2 SENSOR measurements for PIP SPOUT measurements for ADVANCE measurements In SCOPE mode you can use the instrument
19. fuel consumption emissions failure Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 Shut off all accessories start the engine and let it idle in park or neutral After the idle has stabilized check the idle voltage 3 Rev the engine from idle to Wide Open Throttle WOT with a moderate input speed this should only take about 2 seconds don t overrev the engine 4 Let engine speed drop back down to idle for about two seconds 5 Rev the engine again to WOT very quickly and let it drop back to idle again 6 Press the HOLD key to freeze the waveform on the display for closer inspection NOTE It may be advantageous to put the sensor through its paces by using a handheld vacuum pump to see that it generates the correct voltage at a specific vacuum e Reference Waveform VEHICLE INFORMATIONS j S eo Be YEAR 1993 w A MAKE Chevrolet ri MODEL Suburban 1500 av 7 H H ENGINE 5 7L N Ll AP PPAR FUELSYS Throttle Body Fuel Injection oe A l PCM_PIN B13 LtGrn wire at MAP sensor ENG_TMP Operating Temperature R vaj aty ay STATUS KOER Key On Running w RPM Acceleration amp Deceleration OVACUUM 3 24 In Hg d Aa 16V Sms MILEAGE 55011 6 23 Check the manufacturer s specifications for exact voltage range versus vacuum levels and compare them to the readings on the display Generally the sensor voltage
20. hard starts stalls misfires hesitation poor fuel economy Test Procedure NOTE A Capacitive type ignition secondary probe must be used to test the ignition secondary circuit Connecting the CH A or CH B leads directly to an ignition secondary circuit can cause severe damage to the instrument or even personal injury Connect the test leads as displayed by the test tool s HELP Test Procedure and shown in Figure below Figure Testing Secondary Ignition DIS Single 6 66 1 Connect the capacitive type ignition secondary probe to the CH A input terminal and its ground lead to chassis GND 2 Clip the secondary probe to the coil secondary lead wire before the distributor 3 With the Key On Engine Running KOER use the throttle to accelerate and decelerate the engine or drive the vehicle as needed to make the driveability problem or misfire occur 4 If the firing line is negative press C2 to invert the pattern 5 Make sure that the amplitude frequency shape and pulse width are all consistent from cylinder to cylinder Look for abnormalities in the section of the waveform that corresponds to specific components e Reference Waveform VEHICLE INFORMATIONS YEAR 1994 f arc over MAKE Ford or ignition MODEL Explorer voltage ENGINE 4 0L FUELSYS Multiport Fuel Injection voltage PCM_PIN Cyl 1 Spark Plug wire ignition coll begins a STATUS KOER Key On Running Sh PM Ide ENG_TMP Operating Temperat
21. how to stimulate the sensor or operate the circuit to obtain a diagnostic waveform Reference Waveform REF WFM Shows a typical good or normal signal pattern Describes significant waveform features or variations Theory of Operation Explains what the sensor or circuit does and the important signals involved Troubleshooting Tips Tells the symptoms caused by the defective component and how to fix up the problems Function Information Explains about the particular function keys that can be used for the selected test for certain COMPONENTS Pressing Ft moves back through the previous displays to return to active tests or to test selected menus After you choose a preset test you may change most instrument settings to get a better look at the signal You can even change to different display modes moving between Scope mode and GMM mode as needed by pressing the GMM MODE function key in the Scope display or the SCOPE MODE function key in the GMM display You can hold the information in memory at any time by pressing the HOLD key to freeze the display Notice that SAVE RECALL and CLEAR function key labelis displayed above the Function key on the bottom display after how is pressed e Press the SAVE key to save the present screen in the next memory location e Press the RECALL key to recall the screen last saved in memory e Press the CLEAR key to clear all the memory locations e Press the BACK key to resume measuring or to retur
22. injector coil release spike s ranges are from 30 V to 100 V normally NOTE Some injector spike heights are chopped to between 30 V to 60 V by clamping diodes There are usually identified by the flat top on their spike s instead of a sharper point In those cases a shorted injector may not reduce the spike height unless it is severely shorted Troubleshooting Tips Spikes during on time or unusual large turn off spikes indicate the injector driver s malfunction 6 37 Bosch Type Peak and Hold Injector e Theory of Operation Bosch type Peak and Hold injector drivers within the PCM are designed to allow about 4 A to flow through the injector coil then reduce the flow to a maximum of 1 A by pulsing the circuit on and off at a high frequency The other type injector drivers reduce the current by using a switch in resistor but this type drivers reduce the current by pulsing the circuit on and off Current flow pulsed on and off enough to keep hold in winding activated Peak voltage caused by the collapse of the injector coil when Bosch type Peak and Hold injector current is reduced drivers are found on a few European models with MFI systems and some early to mid 1980s Asian vehicles with MFI systems Battery voltage or source voltage supplied to the injector Driver transistor turns on pulling the injector pintle away from its seat starting fuel flow Return to battery o
23. or HI and its ground lead to the sensor output LO or GND 2 With KOEC Key On Engine Cranking or with KOER use the throttle to accelerate or decelerate the engine or drive the vehicle as needed to make the driveability or emissions problem occur 3 Use the Glitch Snare mode to catch dropouts or stabilize waveforms when a sync pulse is created e Reference Waveform VEHICLE INFORMATION PRAE Wane YEAR 1985 MIN 000V MAKE Volkswagen Cranking test of Hall type in dist MODEL Jetta crankshaft position CKP sensor ENGINE 1 8L 10V bs FUELSYS CIS Fuel Injection i rr O 4 NAN aim Th M PCM_PIN 9 GryWht wire HATA AAA UH H STATUS KOEC Key On Cranking oo io ie i RPM Cranking ENG_TMP Operating Temperature VACUUM 51n Hg ay Soa an tAm MILEAGE 105522 The amplitude frequency and shape should be all consistent in the waveform from pulse to pulse The amplitude should be sufficient usually equal to sensor supply voltage the time between pulses repeatable except for sync pulses and the shapes repeatable and predictable Consistency is the key Troubleshooting Tips The duty cycle of the waveform changes only when a sync pulse is displayed Any other changes in duty cycle can mean troubles The top and bottom corners of the waveform should be sharp and voltage transitions of the edge should be straight and vertical Make sure the waveform isn t riding too high off th
24. signal generating analog sensors They generally consist of a wire wrapped soft bar magnet with two connections These two winding or coil connections are the sensor s output terminals When a ring gear a reluctor wheel rotates past this sensor it induces a voltage in the winding A uniform tooth pattern on the reluctor wheel produces a sinusoidal series of pulses having a consistent shape The amplitude is proportional to the rotating speed of the reluctor wheel that is the crankshaft or camshaft The frequency is based on the rotational speed of the reluctor The air gap between the sensor s magnetic tip and the reluctor wheel greatly affects the sensor s signal amplitude They are used to determine where TDC Top Dead Center position is located by creating a synchronous pulse which is generated by either omitting teeth on the reluctor wheel or moving them closer together The PCM uses the CKP sensors to detect misfire When a misfire occurs the amount of time it takes for a waveform to complete its cycle increases If the PCM detects an excessive number of misfires within 200 to 1000 crankshaft revolutions a misfire code OBD II DTC is set Symptoms OBD II DTC s P0340 P0349 P0365 P0369 P0390 P0394 No or hard start intermittent misfire driveability problems e Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With KOER Key On Engine Run
25. the amplitude of the signal It should stay in a predetermined voltage range for a given condition In most cases the amplitude of the waveform should stay at B or battery voltage when the circuit is on and go to 0 V when the switch is activated e Reference Waveform VEHICLE INFORMATIONS Brake pedal YEAR 1993 relsased MAKE Ford ee j MODEL Explorer 15V ENGINE 4 0L FUELSYS Multiport Fuel Injection PCM_PIN 2Lt Grn wire STATUS KOER Key On Running RPM ide ENG_TMP Operating Temperature lepressed here VACUUM 19 In Hg sal Mac f ZAVO 80m MILEAGE 54567 If there is a failure in the circuit the waveform s amplitude will change when it is not supposed to Troubleshooting Tips If the waveform has spikes to ground there may be an open circuit in the power side or a voltage short to ground If the waveform has upward spikes there may be an open in the ground side 6 5 IGNITION TESTS COMPONENT TEST IGNITION TESTS MENU PIP SPOUT DI Primary DI Secondary DIS El Primary DIS El Secondary 6 57 PIP Profile Ignition Pickup SPOUT Spark Output e Theory of Operation The most common electronic ignition system found on Ford vehicles primarily on Ford Lincoln Mercury has been dubbed TFI for Thick Film Ignition This system uses a Hall Switch in the TFI module mounted on the distributor to produce a basic spark timing signal PIP Profile Ignition Pickup This signal is se
26. this test to check the efficiency of the catalytic converter e Reference Waveform VEHICLE INFORMATION Waveform logged about Downstream O2sensor voltage YEAR 1990 40 seconds after startup rises as converter heats up and MAKE Lexus AO2V ali IOS red to MODEL LS400 ENGINE 4 0L FUELSYS Multiport Fuel Injection PCM_PIN 6 OXL1 BIK wire OXL2 24 Grn wire STATUS KOER Key On Running RPM 2500 ENG_TMP Warming UP VACUUM 21 In Hg MILEAGE 79369 B 0 2V Auto f 04V 1s Good O2 sensor s output swing between 100 mV and 900 mV indicates that the O2 sensor is properly signalling PCM to control the fuel mixture The fluctuations in the downstream sensor s signal are much smaller than that of the the upstream sensor As the catalytic converter lights off or reaches operating temperature the signal goes higher due to less and less oxygen being present in the exhaust stream as the catalyst begins to store and use oxygen for catalytic conversion Troubleshooting Tips When a catalytic converter is totally deteriorated the catalytic conversion efficiency as well as the oxygen storage capability of the catalytic converter are essentially lost Therefore the upstream and downstream sensor signals closely resemble one another on an inactive converter t upstream sensor downstream sensor ie j Catalytic Converter OK Catalytic Converter Efficiency poor ECT Engine Coolant Temperature
27. to ground level Knock Sensor e Theory of Operation AC signal generatng Knock Sensors are piezoelectric devices that sense vibration or mechanical stress knock from engine detonation They are quite different from most other AC signal generating automotive sensors that sense the speed or position of a rotating shaft Engine detonation resulting from overadvanced ignition timing can cause severe engine damage Knock sensors supply the PCM sometimes via a spark control module with Knock detection so the PCM can retard ignition timing to prevent further Knocking 6 9 Knock sensors generate a small AC voltage spike when vibration or a knock from detonation occurs The bigger the Knock or vibration the bigger the spike Knock sensors are usually designed to be very sensitive to the Knocking frequencies in 5 to 15 kHz range of the engine block e Symptoms OBD II DTC s P0324 P0334 No AC signal generation at all from Knock Sensors Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the engine block or the sensor wire labeled LO if internally grounded 2 Test 1 With the Key On Engine Running put a load on the engine and watch the Scope display The peak voltage and frequency of the waveform will increase with engine load and RPM increment If the engine is detonating or pinging from too much advanced ignition timing the amplitude and frequency will also increase Test 2 With the
28. value at CURSOR 1 position VOLTS 1 DELTA VOLTS 2 on the INPUT A VOLTS1 DELTA VOLTS2 fom 24V A72V 98V A 130mV A 520mV 650 mV B 240mV A74mV 98 0 mV Sample value at VOLTS CURSOR 1 position on the waveform Sample value at Sample value at VOLTS CURSOR CURSOR 1 position 2 position on the on the INPUT B waveform waveform Volts difference between CURSOR 1 and CURSOR 2 positions Sample value at CURSOR 2 position on the INPUT B waveform Volts difference between CURSOR 1 and CURSOR 2 position on the INPUT B waveform Reading Test Results on the SCOPE Component Tests only Display Measurement results can be displayed as numeric values referred to as readings and wavefom The types of readings depend on the test taking place For example during a O2S SENSOR Zirc test MAXIMUM and MINIMUM values are displayed as readings and during a DUAL O2 SENSOR test MAXIMUM and MINIMUM values of the signals from the oxygen sensor before and after the catalytic converter are displayed as readings During a DI SECONDARY test SPARK VOLTAGE RPM BURN TIME and BURN VOLTAGE are displayed as readings The values you see on the display most often depend on the vehicle under test Refer to the Service Manual of the vehicle manufacturer In Chapter 6 Automotive Diagnostics amp Applications you can find typical results of certain applications 5 3 GMM DISPLAYS The instrument performs cycle by cycle measurements of a
29. variety of signal characteristics in Real Time and plots them as they change with time as a graph The instrument also performs certain other measurements on a continuous basis delivering the results for graphing 20 times per second You can also plot the input signal directly as in SCOPE mode by choosing LIVE The GMM display includes a meter reading showing the current value of the graphed parameter This reading is an average over many result values In some cases measurements are the maximum or minimum of a series of signal values over the most recent 1 second interval The following table shows measurements which can be plotted in GMM displays and the type of graphing and readout DC VOLT DC Average Continuous AC VOLT AC Average Continuous AC DC VOLT AC DC Average Continuous OHM Ohms Continuous DIODE Diode drop Continuous CONTINUITY Continuity Continuous RPM RPM Cycle by Cycle FREQUENCY Frequency Cycle by Cycle DUTY CYCLE Duty Cycle Cycle by Cycle PULSE WIDTH Pulse Width Cycle by Cycle DWELL Dwell Cycle by Cycle IGNITION PEAK VOLTS Ignition Peak Volts Cycle by Cycle IGNITION BURN VOLTS Ignition Burn Volts Cycle by Cycle IGNITION BURN TIME Ignition Burn Time Cycle by Cycle INJECTOR PEAK VOLTS Injector Peak Volts Cycle by Cycle INJECTOR ON TIME Injector On Time Cycle by Cycle TEMPERATURE Temperature C F Continuous LIVE Live Direct input samples Vertical and Horizontal Scaling NOW 723mV HOLD gt ME MAX 895 mV MIN 1
30. vehicle Because this menu is very important for the proper use of the instrument it also appears at power on as the start up display a MENU NX VEHICLE DATA MENU CYLINDERS 4 CYCLES 4 BATTERY 12V VEHICLE DATA IGNITION CONV CYLINDERS 1 2 3 4 default 5 6 8 10 or 12 Specifies the number of cylinders on the vehicle under test CYCLES 2 or 4 default Specifies a two or four stroke engine BATTERY 12 V default or 24 V Specifies battery voltage IGNITION CONV default DIS or DIESEL Specifies the type of ignition system CONV conventional indicates systems using a distributor DIS or El indicates Distributorless Ignition Systems DIESEL indicates ignition systems of Diesel engine Changing Instrument Setup N MENU INSTRUMENT SETUP INSTRUMENT SETUP MENU DISPLAY OPTIONS FILTER AUTO POWER OFF LANGUAGE VERSION INFORMATION SCOPE CALIBRATION DISPLAY OPTIONS MENU USER LAST SETUP You can change the Power On display from VEHICLE DATA MENU default to the last display having been displayed just before the instrument was turned off CONTRAST This setting expressed as a percentage determines the contrast ratio between display text or graphics and the LCD background 0 is all white 100 is all black In practice the percentage will be somewhere between 30 and 80 to have a good readable display GRATICULE Can be set On or Off default is On A dot type graticu
31. 02 mV GMM AUTO Figure 13 Changing Vertical and Horizontal Ranges The vertical and horizontal ranges in GMM displays are manually adjustable by using the Four Way arrow keys The vertical ranges available in GMM displays vary with the measurement being graphed and generally cover the possible output range of the measurement The time ranges available for GMM displays range from 5 sec to 24 hrs per display Auto Power Off will not occur during the GMM mode but to graph for periods of 5 min and longer operate the instrument from external power because operating endurance on internal power is limited to about 4 hours with fresh batteries 5 8 Using Graphing Multimeter GMM r MENU MAIN MENU a COMPONENT TESTS SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP Making Connections GRAPHING MULTIMETER MENU OHM DIODE CONTINUITY RPM FREQUENCY DUTY CYCLE PULSE WIDTH DWELL IGNITION PEAK VOLTS IGNITION BURN VOLTS IGNITION BURN TIME INJECTOR PEAK VOLTS INJECTOR ON TIME AMP DC AC TEMPERATURE C F LIVE INPUT A is used for all GMM tests just except the RPM measurement The probes and test leads to be used depend on the type of test performed When you select certain GMM tests a connection help screen will guide you by pressing sep This tells you which probe or test lead to use and where to connect it Function Key Labels for Each Test Testing Volt DC AC GMM VOLT Press to measure DC A
32. 0369 P0390 P0394 Long cranking time poor fuel economy emissions failure e Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With KOER Key On Engine Running let the engine idle or use the throttle to accelerate or decelerate the engine or drive the vehicle as needed to make the driveability or emissions problem occur 3 Use the Glitch Snare mode to catch dropouts or stabilize waveforms when a sync pulse is created e Reference Waveform VEHICLE INFORMATION PK PK 9 93 V 2 YEAR 1989 MAKE Acura MODEL Legend ENGINE 2 7L 10v FUELSYS Multiport Fuel Injection Pct A amaa PMLPIN C3 OrgBlu a if STATUS KOER Key On Running wv pe RPM ide i 1 ENG_TMP Operating Temperature 1 VACUUM 20 In Hg nid an ARY ms MILEAGE 69050 The amplitude and frequency increase with engine speed RPM The amplitude frequency and shape should be all consistent for the conditions RPM etc the time between pulses repeatable except for sync pulses and the shapes repeatable and predictable Troubleshooting Tips Make sure the frequency of the waveform is keeping pace with engine RPM and that the time between pulses only changes when a sync pulse is displayed This time changes only when a missing or extra tooth on the reluctor wheel passes the sensor That is any other changes in time between the pulses can me
33. 1180 DUR 1 29ms BURN 1 00 kV ATAUANARURBUAUAAAUAI FAI mROMIAEAUANRUATIEA A ZOKV Auto f 50K A10V BIOV Awo f 60V IGNITION DIS SECONDARY IGNITION _PIP SPOUT BACK Figure 8 Single and Dual Input scope in COMPONENT TESTS Use Dual Input Scope mode if you want to simultaneously measure two waveforms one on INPUT A and the other on INPUT B Use SINGLE INPUT SCOPE mode if you want to measure a single signal INPUT B is turned off Use DUAL INPUT SCOPE mode if you want to simultaneously measure two signals Using the Function keys For each test one or more Function Key Labels are displayed depending on the sub selections possible The Labels indicate what the keys do when you press them See the following example IGNITION DI SECONDARY BACK VEHICLE WFM CYLINDER DATA ERASE PARADE Function Key Labels Figure 8 Function Key Labels for SECONDARY IGNITION Pressing a function key that has no label has no effect The same Function Key Label can appear in several tests and it performs a similar function Examples of Function Key Labels CYLINDER Two separate functions can be allowed to the same function key You can use the function key to toggle between the functions When you press FA you can select between PARADE and SINGLE cylinder test F4 When you press ET OHM becomes the active function When you press F2 Diode P becomes the active function When you press F3 Ba CONTINUITY becomes th
34. 20V ma MILEAGE 54567 The idle control output command from the PCM should change when accessories are switched on and off or the transmission is switched in and out of gear DC level should decrease as the IAC solenoid drive current is increased IMPORTANT Before diagnosing IAC solenoid several things must be checked and verified the throttle plate should be free of carbon buildup and should open and close freely the minimum air rate minimum throttle opening should be set according to manufacturer s specifications and check for vacuum leaks or false air leaks Troubleshooting Tips If the engine idle speed doesn t change corresponding with the change of the PCM s command signal suspect a bad IAC solenoid or clogged bypass passage Transmission Shift Solenoid e Theory of Operation The PCM controls an automatic transmission s electronic shift solenoid or torque converter clutch TCC lockup solenoid The PCM opens and closes the solenoid valves using a DC switched signal These solenoid valves in effect control transmission fluid flow to clutch pack servos torque converter lockup clutches and other functional components of the transmission under the PCM s control Some electronic shift solenoid systems use ground feed controlled solenoids that are always powered up and some systems use power feed controlled solenoids that are always grounded A ground feed controlled solenoid on a DC switched circuit appears as
35. 2v Auo f 24V 100 MILEAGE 103128 Frequency stays constant when airflow is constant Frequency increases as airflow increases from snap acceleration Look for pulses that are a full 5 V in amplitude Voltage transitions should be straight and vertical Voltage drop to ground should not exceed 400 mV If greater than 400 mV look for a bad ground at the sensor or the PCM NOTE On some Digital Fast MAF sensors such as the GM Hitachi sensor found on 3800 Buick V 6s the upper left corner of the pulse is rounded off slightly This is normal and doesn t indicate a bad sensor Troubleshooting Tips Possible defects to watch for are runted shortened pulses unwanted spikes and rounded off corners that could all have the effect of garbling an electronic communication causing a driveability or emissions problem The sensor should be replaced if it has intermittent faults Digital Karman Vortex MAF Mass Air Flow Sensor e Theory of Operation Karman Vortex type MAF sensors are usually manufactured as part of the air cleaner assembly They are commonly found on Mitsubishi engine systems While most digital MAF sensors vary only their frequency with changes in airflow rate the Karman Vortex type s signal varies Pulse Width as well as Frequency with changes in airflow rate As the airflow increases the frequency of the signal generated increases Karman Vortex sensors differ from other digital MAF sensors during acceleration modes During
36. 5 Make sure that all the hoses and lines to and from the intake manifold EGR valve and vacuum solenoid valve are all intact and routed properly with no leaks Make sure the EGR valve diaphragm can hold the proper amount of vacuum Make sure that the EGR passageways in and around the engine are clear and unrestricted from internal carbon buildup 6 Use the Glitch Snare mode to check for signal dropouts Reference Waveform VEHICLE INFORMATIONS YEAR 1990 i MAKE Chevrolet i a I MODEL Suburban 15V j Hit 1 ENGINE 5 7L Pre Diet rh Reet Fe PPP PAFA FUELSYS Throttle Body Fuel Injection I4 Jf PCM_PIN A4 Gry wire Ig STATUS KOER Key On Running ow brara brett RPM __ Light Acceleration fan ENG_TMP Operating Temperature circuit here VACUUM 12 23 In Hg sv ae ee MILEAGE 59726 As soon as the engine reaches the predetermined EGR requirement conditions the PCM should begin pulsing the EGR solenoid with a pulse width modulated signal to open the EGR solenoid valve EGR demands are especially high during accelerations 6 41 Troubleshooting Tips If the waveform has runted shortened spike heights it indicates a shorted EGR vacuum solenoid If the waveform has a flat line no signal at all it indicates a PCM failure PCM s EGR conditions not met or wiring or connector problem Too much EGR flow can make the vehicle hesitate loose power or even stall Not enough EGR flow can result in emi
37. Display The last display having been displayed just before the instrument was turned off RMS Vertical Scale The scale used for vertical display vertical sensitivity expressed in certain units per Engine speed expressed in Rotations Per Minute of the crankshaft division Cc wn Ww Universal Serial Bus visit www usb org for details Terminology Voltage Drop Wastegate Waveform WOT Voltage lose across a wire connector or any other conductor Voltage drop equals resistance in ohms times current in amperes ohm s Law A valve used to limit charge air pressure by allowing exhaust gases to bypass the turbocharger The pattern defined by an electrical signal Wide Open Throttle Menu Overview MAIN MENU COMPONENT TESTS SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP GRAPHING MULTIMETER MENU VOLT DC AC OHM DIODE CONTINUITY RPM FREQUENCY DUTY CYCLE PULSE WIDTH DWELL IGNITION PEAK VOLTS IGNITION BURN VOLTS IGNITION BURN TIME INJECTOR PEAK VOLTS INJECTOR ON TIME AMP DC AC TEMPERATURE C F LIVE INSTRUMENT SETUPMENU FILTER MENU DISPLAY OPTIONS INPUT A OFF FILTER INPUT B OFF AUTO POWER OFF LANGUAGE VERSION INFORMATION SCOPE CALIBRATION COMPONENT TESTS MENU SENSORS ACTUATORS ELECTRICAL IGNITION or DIESEL VEHICLE DATA MENU CYLINDERS 4 CYCLES 14 BATTERY 12V IGNITION CONV IGNITION MENU CONV default DIS DIESEL DISPLAY OPTIONS MENU
38. E C F LIVE COMPONENT TESTS MENU SENSORS ACTUATORS ELECTRICAL IGNITION or DIESEL VEHICLE DATA MENU CYLINDERS 4 CYCLES 14 BATTERY 12V IGNITION CONV IGNITION MENU CONV default DIS DIESEL FILTER MENU INPUT A OFF INPUT B OFF INSTRUMENT SETUPMENU DISPLAY OPTIONS FILTER AUTO POWER OFF LANGUAGE VERSION INFORMATION SCOPE CALIBRATION DISPLAY OPTIONS MENU USER LAST SETUP OFF i CONTRAST 4 GRATICULE ON HORIZ TRIG POS 10 i ACQUIRE MODE PEAK DETECT LANGUAGE MENU LANGUAGE ENGLISH AUTO POWER OFF MENU AUTO POWER OFF ON AUTO POWER OFF TIME 30 min DIESEL MENU DIESEL INJECTOR ADVANCE SENSOR TESTS MENU ABS Sensor Mag O2S Sensor Zirc Dual O2 Sensor ECT Sensor Fuel Temp Sensor IAT Sensor Knock Sensor TPS Sensor CKP Magnetic CKP Hall CKP Optical CMP Magnetic CMP Hall CMP Optical VSS Magnetic VSS Optical MAP Analog MAP Digital MAF Analog MAF Digi Slow MAF Digi Fast MAF Karman Vrtx EGR DPFE ACTUATOR TESTS MENU Injector PFI MFI Injector TBI Injector PNP Injector Bosch Mixture Cntl Sol EGR Cntl Sol IAC Motor IAC Solenoid Trans Shift Sol Turbo Boost Sol Diesel Glow Plug ELECTRICAL TESTS MENU Power Circuit V Ref Circuit Ground Circuit Alternator Output Alternator Field VR Alternator Diode Audio System DC Switch Circuits IGNITION TESTS MENU PIP SPOUT DI Primary DI Secondary DIS Primary DIS Seco
39. GLE 0 EYS A B shor TRIGGER moya AAAA Y SCOPE SINGLE SHOT nae l Sa ee Bai TEST MOVE a CED Cre CF Crs Press to repeat a single shot acquisition Trigger Control Functions TRIGGER is a set of conditions that determine whether and when acquisitions start The following will determine the trigger conditions Select INPUT A or TRIGGER as the TRIGGER SOURCE input Use AUTO or NORMAL acquisitions e Select trigger to occur on a positive or negative SLOPE of the signal SET the trigger LEVEL If you change the trigger level the AUTO RANGE function is turned off When you are in SCOPE you can control the trigger functions as follows SCOPE INPUT INPUT SINGLE lt lt EYS A B SHOT rnvcoen Press to select the trigger level adjustment ODED E T Ee raeee SCOPE TRIGGER BACK MODE SLOPE er va uae D CGY G2 GD CO GD Press to select the trigger source Press to select DC or AC Press to select AUTO or NORMAL acauisitions ___ __ Press to select the trigger slope 5 4 AUTO versus NORMAL acquisitions If you select AUTO the instrument always performs acquisitions i e it always displays the signals on the input If NORMAL is selected a trigger is always needed to start an acquisition TRIGGER SLOPE If you select trigger occurs at a rising positive edge of the signal If you select a trigger occurs at a falling negative edge of the signal TRIGGER SOURCE
40. GT af ADE voltage F 3 i Press to measure AC true rms voltage REPET Press to start plotting a new TEST graph as new samples are 2 CF CF Cr acquired Press to reset maximum and minimum Press to measure AC DC true rms voltage You can stop graphing by pressing HOLD key on the instrument Testing Resistance Diode and Continuity Use this menu option to test resistance diode forward voltage and the continuity of wiring and connections Connect the test lead tip and test lead ground across the object to be tested GMM OHM CONTINUTY Press to measure am OPEN CLOSE resistance GD F2 F3 F4 Press to test diodes Press to test continuity of wiring and connections If you select OPEN the instrument beeps when the tested connection is open If you select CLOSE it beeps when the tested connection is closed OFL is displayed when the resistance is outside the instrument s maximum range This occurs when the resistance of the sensor is too high or the connection to the sensor is interrupted or open To test a diode the instrument sends a small current through the diode to test the voltage across it Depending on the type of diode this voltage should be in the range from 300 to 600 mV A diode that has an internal short will display about 0 V OFL is displayed when the diode is defective or when it is connected in reverse If you are not certain about the polarity of the diode try the reverse connection I
41. H A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With KOER Key On Engine Running let the engine idle or use the throttle to accelerate or decelerate the engine or drive the vehicle as needed to make the driveability or emissions problem occur 3 Use the Glitch Snare mode to catch dropouts or stabilize waveforms when a sync pulse is created e Reference Waveform VEHICLE INFORMATION FREQ 35 7 Hz i YEAR 1989 MIN 138 ane Whaat MAKE Mitsubishi increasing engine RPM MODEL Montero ev ENGINE 3 0L wifi FUELSYS Multiport Fuel Injection 1 Hil PCM_PIN 23 Red wire at PCM wi STATUS KOER Key On Running C DEE ea RPM Idle ENG_TMP Operating Temperature VACUUM 20 In Hg al Auto f 18v E MILEAGE 184066 The amplitude frequency and shape should be all consistent in the waveform from pulse to pulse The amplitude should be sufficient the time between pulses repeatable except for sync pulses and the shapes repeatable and predictable Consistency is the key Troubleshooting Tips The duty cycle of the waveform changes only when a sync pulse is displayed Any other changes in duty cycle can mean troubles The top and bottom corners of the waveform should be sharp However the left upper corner may appear rounded on some of the higher frequency high data rate optical distributors This is normal Optical CMP sensors are very susceptible to malf
42. Key On Engine Off tap the engine block lightly near the sensor with a small hammer or a ratchet extension Oscillations will be displayed immediately following a tap on the engine block The harder the tap the larger the amplitude of the oscillations Reference Waveform VEHICLE INFORMATION Typical Knock Sensor test YEAR 1993 Note signal goes above and below zero volts AC MAKE Ford Logged during slight acceleration g 0 1V 1 MODEL F150 4WD Pickup ENGINE 5 0L oti L Hin ht Eo ee Pos Pin23 Yel Red wire OV STATUS KOER Key On Running i RPM Slightly Accelerate ENG_TMP Operating Temperature Mae me ee 1i VACUUM 19 In Hg MILEAGE 66748 Troubleshooting Tips Knock sensors are extremely durable and usually fail from physical damage to the sensor itself The most common type of Knock Sensor failure is not to generate a signal at all due to its physical damage when the waveform stays flat even if you rev the engine or tap on the sensor In this case check the sensor and the instrument connections make sure the circuit is not grounded then condemn the sensor Throttle Position Sensor TPS e Theory of Operation A TPS is a variable resistor that tells the PCM the position of the throttle that is how far the throttle is open whether it is opening or closing and how fast Most throttle position sensors consist of a contact connected to the throttle shaft which slides over a section of resistance material
43. MM IGNITION BURN VOLTS IGNITION PEAK VOLTS IGNITION BURN VOLTS IGNITION BURN TIME CED ED Gd Cs Cs Press to test the pulse width of the signal If you select the width of the negative going pulse is displayed If you select the width of the positive going pulse is displayed GMM IGNITION BURN TIME INVERT REPEAT MAX MIN TEST RESET CD ED C Press to invert the displayed ignition waveform INVERT REPEAT MAX MIN TEST RESET CED ED C gt INVERT REPEAT MAX MIN OFF TEST RESET Cra CF CFs SINGLE cylinder waveform Seger ete SPARK VOLTAGE BURN VOLTAGE i BURN TIME Testing Injector Peak Volts and On Time cf MENU GRAPHING MULTIMETER INJECTOR PEAK VOLTS INJECTOR ON TIME GMM INJECTOR PEAK VOLTS GMM INJECTOR ON TIME REPEAT MAX MIN REPEAT MAX MIN TEST RESET TEST RESET CFs CFs CF CFs PEAK VOLTS a INJECTION PULSE WIDTH ON TIME Testing Dwell The test is done with the shielded test lead on INPUT A connected to the primary side of the ignition coil GMM DWELL VEHICLE DWELL MAX MIN DATA RESET GCD CED C Press to select between readings in degrees crankshaft rotation or in ms Testing Current Use this menu option to test current with a current probe optional accessory GMM AMPERES RANGE REPEAT AC AC DC EA TEST Press to measure DC current CEN F2 CED Fa GD Press to measure Press to select between AC true r
44. MPONENT TESTS e SCOPE e GRAPHING MULTIMETER The fastest way to set up the instrument to test most devices and circuits is to choose from one of the built in COMPONENT TESTS These tests preset the instrument to either Single or Dual Input Scope mode Most instrument settings may be adjusted manually once you have chosen a Component Test enabling you to fine tune settings to get a better look at the signal Changes you make to settings specific to a Component Test are temporary and are restored to their preset values each time another test is chosen When configured for a specific Component Test the instrument displays the reference waveform and data as well as the name of the test on the bottom display along with the Function Key Labels specific to the test chosen If you prefer total control over your instrument configuration choose SCOPE test mode from the MAIN MENU Settings for SCOPE are separately preserved and restored each time you choose SCOPE from the MAIN MENU These settings are not affected when you choose a Component Test This is also true for the GRAPHING MULTIMETER test mode so in effect they are custom setups 5 2 SCOPE DISPLAYS Using Single and Dual Input Scope Mode The instrument can be configured to show scope displays for either CH A or CH B signals In DUAL INPUT SCOPE mode both CH A and CH B may be displayed at the same time Use SINGLE INPUT SCOPE mode if you want to measure a single signal INPUT B is turned of
45. Mixture Cntl Sol EGR Cntl Sol IAC Motor IAC Solenoid Trans Shift Sol Turbo Boost Sol Diesel Glow Plug 6 32 Saturated Switch Type MFI PFI SFl Injector Theory of Operation The fuel injector itself determines the height of the release spike The injector driver switching transistor determines most of the waveform features Generally an injector driver is located in the PCM that turns the injector on and off Different Kinds Saturated Switch type Peak and Hold type Bosch type Peak and Hold and PNP type of injector drivers create different waveforms Knowing how to interpret injector waveforms determining on time referencing peak height recognizing bad drivers etc can be a very valuable diagnostic talent for driveability and emission repair Saturated switch injector drivers are used primarily on multiport fuel injection MFI PFI SFI systems where the injectors are fired in groups or sequentially Determining the injector on time is fairly easy The injector on time begins where the PCM grounds the circuit to turn it on and ends where the PCM opens the control circuit Since the injector is a coil when its electric field collapses from the PCM turning it off it creates a spike Saturated Switch type injectors have a single rising edge The injector on time can be used to see if the Feedback Fuel Control System is doing its job Symptoms Hesitation rough idle intermittent stall at idle poor fuel mileage emiss
46. NFORMATIONS MAX 40 mV YEAR 1986 Tests voltage drop across ground circuit MAKE Oldsmobile MODEL Toronado CH A probe connected to engine block ENGINE 3 8L COM probe connected to battery negative gees Test conducted w engine running FUELSYS Multiport Fuel Injection PCM_PIN CH Aon Engine Block 200mV COM on Battery Negative OV pnra wl STATUS KOER Key On Running 200mv RPM Idle i ENG_TMP Operating Temperature aie roe gt aoe VACUUM 18 In Hg MILEAGE 123686 Average voltage drop should not exceed 100 300 mV If there is too much resistance in the ground circuit the waveform s amplitude will be too high Troubleshooting Tips If average voltage drop is excessive clean or replace the connections and cables Alternator Output Theory of Operation Alternators replaced generators due to their higher output at low engine speed and their more compact and lightweight design An alternator is an AC generator with diode rectification which converts the AC signal to a pulsating DC signal The DC signal charges the vehicle s battery and supplies power to run the vehicle s electrical and electronic systems Field current is supplied to the rotor in the alternator to vary its output Alternator output voltage increases as engine RPM increases The alternator s output voltage is controlled by a solid state regulator within the PCM in some cases The regulator limits the charging
47. NTINUITY RPM FREQUENCY DUTY CYCLE PULSE WIDTH DWELL IGNITION PEAK VOLTS IGNITION BURN VOLTS IGNITION BURN TIME INJECTOR PEAK VOLTS INJECTOR ON TIME AMP DC AC TEMPERATURE C F LIVE INSTRUMENT SETUP MENU DISPLAY OPTIONS AUTO POWER OFF LANGUAGE VERSION INFORMATION SCOPE CALIBRATION LANGUAGE MENU LANGUAGE ENGLISH COMPONENT TESTS MENU SENSORS ACTUATORS ELECTRICAL IGNITION or DIESEL VEHICLE DATA MENU CYLINDERS 4 CYCLES 14 BATTERY 12V IGNITION CONV IGNITION MENU CONV default DIS DIESEL DISPLAY OPTIONS MENU USER LAST SETUP OFF CONTRAST 4 GRATICULE ON HORIZ TRIG POS 10 ACQUIRE MODE PEAK DETECT AUTO POWER OFF MENU AUTO POWER OFF ON AUTO POWER OFF TIME 30 min pE 1 DIESELMENU DIESEL INJECTOR Figure 6 Automotive Test Functions amp Setups Overview SENSOR TESTS MENU ABS Sensor Mag O2S Sensor Zirc Dual O2 Sensor ECT Sensor Fuel Temp Sensor IAT Sensor Knock Sensor TPS Sensor CKP Magnetic CKP Hall CKP Optical CMP Magnetic CMP Hall CMP Optical VSS Magnetic VSS Optical MAP Analog MAP Digital MAF Analog MAF Digi Slow MAF Digi Fast MAF Karman Vrtx EGR DPFE ACTUATOR TESTS MENU Injector PFI MFI Injector TBI Injector PNP Injector Bosch Mixture Cntl Sol EGR Cnil Sol IAC Motor IAC Solenoid Trans Shift Sol Turbo Boost Sol Diesel Glow Plug ELECTRICAL TESTS MENU Power Circuit V Ref Circuit Ground Circuit Alter
48. P and crankshaft CKP position sensors e Engine vacuum balance viewed from an analog MAP sensor signal Knock sensors KS Frequency Modulated Signals The types of sensors or devices in a vehicle that produce Frequency Modulated signals are e Digital mass airflow MAF sensors e Ford s digital MAP sensors Optical vehicle speed sensors VSS e Hall Effect vehicle speed sensors VSS Optical camshaft CMP and crankshaft CKP position sensors Hall Effect camshaft CMP and crankshaft CKP position sensors Pulse Width Modulated Signals The types of circuits of devices in a vehicle that produce Pulse Width Modulated signals are e Ignition coil primary e Electronic spark timing circuits EGR purge turbo boost and other control solenoids e Fuel injectors Idle air control motors and solenoids Serial Data Multiplexed Signals The types of circuits or devices in a vehicle that produce Serial Data signals are e Powertrain control modules PCM Body control modules BCM ABS control modules Other control modules with self diagnostics or other serial data communications capability 3 1 3 2 CRITICAL CHARACTERISTICS OF AUTOMOTIVE ELECTRONIC SIGNALS Only 5 critical characteristics or information types given from the Automotive electronic signals are important because the vehicle s PCM considers them important e Amplitude The voltage of the electronic signal at a certain point in time e Freque
49. PCM s V Ref circuit another wire provides the sensor ground and the third wire is the sensor s signal output to the PCM Generally Ford s DPFE sensors are found on late model 4 0 L Explorers and other vehicles and produce just under 1 V with no exhaust gas pressure and close to 5 V with maximum exhaust gas pressure NOTE Ford s PFE sensors produce 3 25 V with no exhaust back pressure increasing to about 4 75 V with 1 8 PSI of exhaust back pressure On propery operating vehicles the voltage won t ever getto 5 V PFE sensors can be found on many Taurus and Sable models Symptoms OBD II DTC s P0400 P0408 Hesitation engine pinging idle problems I M emission test failure Test Procedure 1 Connect the CH A lead to the sensor output HI and its ground lead to the sensor output LO or GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System is able to enter closed loop Verify this by viewing the O2 sensor signal if necessary 3 Shut off A C and all other accessories Drive the vehicle under normal driving modes start from dead stop light acceleration heavy acceleration cruise and deceleration 4 Make sure that the amplitude is correct repeatable and present during EGR conditions The sensor signal should be proportional to exhaust gas versus manifold vacuum pressures 5 Make sure that all the hoses and lines to and from the intake man
50. STATUS KOBD Key On Driven w Laneaetttymnnetemnahaeenrnee M 1500 ENG_TMP Operating Temperature VACUUM 19 In Hg sw ee pee ms MILEAGE 54567 The drive signal should be consistent and repeatable Troubleshooting Tips If the waveform appears as a flat line no signal at all it can indicate a PCM failure PCM conditions not met shift points TCC lockup etc or wiring or connector problems Turbo Boost Control Solenoid e Theory of Operation Turbochargers increase horsepower considerably without increasing engine piston displacement Turbochargers also improve torques over the useful RPM range and fuel economy and reduces exhaust gas emissions Turbocharger s boost pressure must be regulated to obtain optimum acceleration throttle response and engine durability Regulating the boost pressure is accomplished by varying the amount of exhaust gas that bypasses the exhaust side turbine As more exhaust gas is routed around the turbine the less boost pressure is increased 6 45 A door called the wastegate is opened and closed to regulate the amount of bypass The wastegate is controlled by a vacuum servo motor which can be controlled by a vacuum solenoid valve that receives a control signal from the PCM When the PCM receives a signal from the MAP sensor indicating that certain boost pressure is reached the PCM commands the vacuum solenoid valve to open in order to decrease boost pressure The PCM opens the solenoi
51. Sensor e Theory of Operation Most ECT sensors are Negative Temperature Coefficient NTC type thermistors This means they are primarily two wire analog sensors whose resistance decreases when their temperature increases They are supplied with a 5 V V Ref power signal and return a voltage signal proportional to the engine coolant temperature to the PCM When this instrument is connected to the signal from an ECT sensor what is being read is the voltage drop across the sensor s NTC resistor Typically ECT sensor s resistance ranges from about 100 000 ohms at 40 F 40 C to about 50 ohms at 266 F 130 C The ECT sensor signal is used by the PCM to control closed loop operation shift points torque converter clutch operation and cooling fan operation e Symptoms OBD II DTC s P0115 P0116 P0117 P0119 No or hard start high fuel consumption emissions failure driveability problems Test Procedure 1 Backprobe the terminals on the ECT sensor with the CH A lead and its ground lead 2 Run the engine at idle and monitor the sensor voltage decrease as the engine warms Start the engine and hold the throttle at 2500 RPM until the trace goes across the screen 3 Set the time base to 50 sec div to see the sensor s entire operating range from stone cold to operating temperature 6 6 4 Press the HOLD key to freeze the waveform on the display for closer inspection 5 To measure resistance disconnect the sen
52. Sensor MAP Analog IAT Sensor MAP Digital Knock Sensor MAF Analog TPS Sensor MAF Digi Slow CKP Magnetic MAF Digi Fast CKP Hall MAF Karman Vrtx CKP Optical EGR DPFE CMP Magnetic ABS Sensor Magnetic e Theory of Operation ABS Ant lock Brake System wheel speed sensors generate AC signals with frequency proportional to wheel speed The amplitude peak to peak voltage increases as the wheel speed increases and is greatly affected by air gap between the magnetic tip and the reluctor wheel The ABS computer compares the frequencies and uses this information to maintain wheel speeds while braking This test shows the sensor s raw output signal or the frequency proportional to wheel speed The sensor s output signal should be continuous as long as the wheel rotates Spikes or distortion of individual output pulses may indicate occasional contact between the sensor and the reluctor wheel Symptoms ABS light on no ABS signal generation e Test Procedure 1 Connect the shielded test lead to the CH A input and connect the ground lead of the test lead to the sensor output LO or GND and the test lead probe to the sensor output or HI Use a wiring diagram for the vehicle being serviced to get the ABS control unit pin number or color of the wire for this circuit 2 Drive vehicle or spin the wheel by hand to generate signal When driving vehicle back probe the connector leading to the sensor Place the transmission in drive and slo
53. TIONS 6 1 COMPONENT TESTS Preset Operation The instrument provides predefined setups for a variety of vehicle sensors and circuits To choose a preset test select COMPONENT TESTS from the MAIN MENU From the resulting menu select a test group e SENSORS e ACTUATORS ELECTRICAL e IGNITION Then select a specific test from those listed Each test places the instrument in a configuration best suited to display signals for the chosen device or circuit Once a test has been selected you can obtain some useful reference informations specific to that test at any time by pressing the HELP key as previously described In some cases there are more than one test for a particular device If you are not sure which test to use the descriptions to the tests in the following sections would help you decide When you want to test a device for which no test is provided choose a test for a similar device For example to test a temperature sensor not listed try the Fuel Temp Sensor test Or choose SCOPE from the MAIN MENU and configure the instrument manually as needed After you chose a preset test you may change most instrument settings as needed to get a better look at the signal You can even change the display type between SCOPE mode and GMM mode 6 2 SENSOR TESTS fr MENU SENSOR TESTS MENU SENSOR TESTS MENU ABS Sensor Mag CMP Hall O2S Sensor Zirc CMP Optical EME Dual O2 Sensor VSS Magnetic SENSORS ECT Sensor VSS Optical Fuel Temp
54. Tips The top and bottom corners of the waveform should be sharp and voltage transitions of the edge should be straight and vertical All of the waveforms should be equal in height due to the constant supply voltage to the sensor Make sure the waveform isn t riding too high off the ground level This could indicate a high resistance or bad ground supply to the sensor Voltage drop to ground should not exceed 400 mV Look for abnormalities observed in the waveform to coincide with a driveability problem or a DTC 6 22 Analog Manifold Absolute Pressure MAP Sensor e Theory of Operation Almost all domestic and import MAP sensors are analog types in design except Ford s MAP sensor Analog MAP sensors generate a variable voltage output signal that is directly proportional to the intake manifold vacuum which is used by the PCM to determine the engine load They are primarily three wire sensors and are supplied with 5V V Ref power a ground circuit and the signal output to the PCM High pressure occurs when the engine is under a heavy load and low pressure high intake vacuum occurs when there is very little load A bad MAP sensor can affect the air fuel ratio when the engine accelerates and decelerates It may also have some effect on ignition timing and other PCM outputs A bad MAP sensor or its hose can trigger DTC s for MAF TP or EGR sensors e Symptoms OBD II DTC s P0105 P0109 Low power stall hesitation excessive
55. V until the ignition key is switched on Symptoms No or hard start emissions with excessive smokes excessive combustian noises knocks e Test Procedure 1 Set the instrument up with the current probe Connect the probe to the CH A Adjust the probe to read DC Zero Clamp the current probe around the glow plug feed wire With the diesel engine stone cold turn on the ignition key and watch for the readings a A WwW PY Make sure that the amplitude of the current is correct and consistent for the glow plug systems under test e Reference Waveform VEHICLE INFORMATIONS YEAR 1977 ES MAKE Mercedes Benz j i MODEL 240D 60A ENGINE 2 4L 404 ais Fal FUELSYS Multiport Fuel Injection a a i ne PCM_PIN Power supply to glow plugs switched on STATUS KOEO Key On Engine Off Current begins f RPM 0 to flow through OA glow plugs ENG_TMP Ambient Temperature VACUUM 01n Hg mn JAA OU MILEAGE 151417 6 47 Look for the current going through the glow plug to be atits maximum when the ignition key is switched on Maximum current and operating current specifications may be available from the manufacturer s service manual All glow plugs should draw about the same current under cold or hot conditions Troubleshooting Tips If the waveform stays flat at 0 V suspect a faulty glow plug If the waveform has drop outs suspect an open circuit in the glow plug s heating elemen
56. agine the frequency graph from an ABS sensor with an occasional dropout due to an intermittent short in the cable As the wheel spins the frequency output is stable until it briefly drops out due to the short A graph of the frequency shows a stable value until the short occurs At that instant the graph show a sharp spike downward indicating that the frequency went to zero Now imagine being able to set trigger thresholds above and below the stable frequency value shown on the graph so that when the downward spike on the graph occurs a trigger event is generated This is the essence of Glitch Snare operation When ordinary scopes try to detect dropouts and other sudden changes in continuous AC signals the majority of the signal is ignored because these instruments only display new waveforms at the rate of a few per second Therefore it is not easy for them to capture and display the occasional glitch or dropout And if an interesting event does happen to be captured it is soon overwritten with the next normal event making detailed examination impossible The Glitch Snare operation triggers only on abnormal signal conditions which virtually guarantees you ll catch the first event to come along The captured signal waveform remains displayed in the Glitch Snare display for you to examine until it is overwritten by the next unusual event What s more by enabling the Auto Save option each new event to be detected is automatically saved to Memory
57. al standard for serial data communication to which the optical interface of the chamber of an engine instrument conforms Lamda Sensor Oxygen or O2 sensor Electromagnetic Mutual disturbance of signals mostly caused by signals from adjacent wiring LCD Liquid Crystal Display Interference EMI Electromagnetic Interference Link i i General tem used to indicate the existence of communication facilities between two points Electrical Electronic Feed Controlled Circuit A circuit that is energized by applying voltage it has already been grounded Manifold A device designed to collect or distribute fluid air or the like Filter Electrical circuits or device that only passes or blocks certain signal frequencies An application can be to remove noises from a signal Fani Groung Aconductor ihat wil oissipate large electrica CURES NOME Earth Intermittent Irregular a condition that happens with no apparant or predictable pattern ECM Electronic Control Module on a vehicle j Invert To change to the opposite polarity Puts the waveform display upside down FGU Eletronic COntOl Unit on a venicIe Knock Engine The sharp metallic sound produced when two pressure fronts collide in the combustion Master Reset Resets the instrument to the factory Default Setup You can do this by turning power on while pressing the F5 function key CFS Freeze Frame A block of memory containing the vehicle operating conditions for a specific time Menu A li
58. an trouble Look for abnormalities observed in the waveform to coincide with an engine sputter or driveability problem Hall Effect Camshaft Position CMP Sensor e Theory of Operation These CMP sensors are classified as CMP Sensors Low Resolution in industry The Hall CMP sensors are low resolution accuracy digital sensors which generate the CMP signal that is a low frequency tens of Hz square wave switching between zero and V Ref from a Hall sensor The Hall CMP sensor or switch consists of an almost completely closed magnetic circuit containing a permanent magnet and pole pieces A soft magnetic vane rotor travels through the remaining air gap between the magnet and the pole piece The opening and closing of the vane rotor s window interrupts the magnetic field causing the Hall sensor to turn on the off like a switch so some vehicle manufacturers call this sensor a Hall switch These sensors operate at different voltage levels depending on the vehicle manufacturers and deliver a series of pulses as the shaft rotates They are used to switch the ignition and or fuel injection triggering circuits on and off The PCM uses the Hall CMP sensors to detect misfire e Symptoms OBD II DTC s P0340 P0349 P0365 P0369 P0390 P0394 Long cranking time poor fuel economy emissions failure e Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 Wi
59. arburetor ov voltage pr PCM_PIN CHA to Negative side of ignition coil STATUS KOER Key On Running RPM ide enarging Nee pono ENG_TMP Operating Temperature VACUUM 20 In Hg ai Aua F450 me MILEAGE 140241 The Ignition Peak voltage and Burn voltage measurements are available in this test but they should be corrected to account for the turns ratio of the coil windings Look closely to see that the pulse width dwell changes when engine load and RPM changes e Troubleshooting Tips Look for the drop in the waveform where the ignition coil begins charging to stay relatively consistent which indicates consistent dwell and timing accuracy of individual cylinder Look for a relatively consistent height on the arc over voltage or firing line A line that is too high indicates high resistance in the ignition secondary due to an open or bad spark plug wire or a large spark gap A line that is too short indicates lower than normal resistance in the ignition secondary due to fouled cracked or arcing spark plug wire etc Look for the spark or burn voltage to remain fairly consistent This can be an indicator of air fuel ratio in the cylinder If the mixture is too lean the burn voltage may be higher and if too rich the voltage may be lower than normal 6 60 Look for the burn line to be fairly clean without a lot of hash noise A lot of hash can indicate an ignition misfire in the cylinder due to over advanced i
60. ark gap A line that is too short indicates lower than normal resistance in the ignition secondary due to fouled cracked or arcing spark plug wire etc Look for the spark or burn voltage to remain fairly consistent This can be an indicator of air fuel ratio in the cylinder If the mixture is too lean the burn voltage may be higher and if too rich the voltage may be lower than normal Look for the burn line to be fairly clean without a lot of hash A lot of hash can indicate an ignition misfire in the cylinder due to over advanced ignition timing bad injector fouled spark plug or other causes Longer bum lines over 2 ms can indicate an abnormally rich mixture and shorter bum lines under 0 75 ms can indicate an abnormally lean mixture Look for at least 2 preferably more than 3 oscillations after the burn line This indicate a good ignition coil a good condenser on point type ignitions DIS Distributorless Ignition System Primary e Theory of Operation The DIS or El primary ignition test is an effective test for locating ignition problems that relate to El ignition coils The waveform is very useful because occurrences in the ignition secondary burn are induced back into the primary through mutual induction of the primary and secondary windings The waveform is primarily used to 1 analyze individual cylinder dwell coil charging time 2 analyze ignition coil and secondary circuit performance from the firing line 3
61. around the pivot axis for the movable contact The TPS is a three wire sensor One of the wires is connected to an end of the sensor s resistance material and provides 5 V via the PCM s V Ref circuit another wire is connected to the other end of the resistance material and provides the sensor ground GND The third wire is connected to the movable contact and provides the signal output to the PCM The voltage at any point in the resistance material is proportional to the throttle angle as sensed through the movable contact The voltage signal returning to the PCM is used to calculate engine load ignition timing EGR control idle control and other PCM controlled parameters such as transmission shift points A bad TPS can cause hesitation idle problems high emissions and Inspection Maintenance I M test failures Generally throttle position sensors produce just under 1 V with the throttle closed and produce just under 5 V with the throttle wide open WOT The PCM determines the sensor s performance by comparing the sensor output to a calculated value based on MAP and RPM signals e Symptoms OBD II DTC s P0120 P0124 P0220 P0229 Hesitation stall at stops high emissions I M test failures transmission shifting problems Test Procedure 1 Connect the CH A lead to the output or signal circuit of TPS and its ground lead to the TPS s GND 2 With KOEO slowly sweep the throttle from closed to the wide open position WOT a
62. as a dual trace oscilloscope with INPUT A and INPUT B connected 4 7 COM TRIGGER Used as external trigger for probes with dual banana plugs such as the RPM Inductive Pickup TRIGGER as single input Used in SCOPE mode to trigger or start acquisitions from an external source COM as single input Used for safety grounding when the Capacitive Secondary Pickup is connected to the ignition system AN WARNING TO AVOID ELECTRICAL SHOCK CONNECT THE COM INPUT OF THE INSTRUMENT TO VEHICLE GROUND BEFORE CLAMPING THE CAPACITIVE SECONDARY PICKUP SUPPLIED ON THE IGNITION WIRES THIS GROUND CONNECTION IS REQUIRED IN ADDITION TO THE NORMAL MEASUREMENT GROUND CONNECTIONS For other tests the COM input should not be connected to engine ground when the probes have their own ground connection at the probe end See the GROUNDING GUIDELINES 4 5 GROUNDING GUIDELINES Incorrect grounding can cause various problems 1 A ground loop can be created when you use two ground leads connected to different ground potentials This can cause excessive current through the grounding leads INPUT A Incorrect Grounding Correct Grounding Ground Loop by Double Grounding on Shield of Test Lead Connected to Ground Different Grounds 2 Excessive noise shown on the measured signal INPUT A COM Incorrect Grounding Noise Pickup on Unshielded Ground Lead 3 Measurement faults or short circuit with the DUAL INPUT SCOPE mode This occ
63. ase 3 Raise the engine to 2500 RPM and hold it steady The injector on time will modulate from slightly larger to slightly smaller as the system controls the mixture Generally the injector on time only has to change from 0 25 ms to 0 5 ms to drive the system through its normal full rich to full lean range 4 Use the Glitch Snare mode to check for sudden changes in the injector on time e Reference Waveform VEHICLE INFORMATIONS MAX 83 A M YEAR 1993 DUR 5 51 ms MAKE Chevrolet GOV MODEL Suburban 1500 i ENGINE 5 7L 2V FUELSYS Throttle Body Fuel Injection 6 ain en aa o A PCM_PIN A16 DkBlu Si ji ji f 7 Hedi ake ieee STATUS KOER Key On Running good injector driver RPM Snap Acceleration ENG_TMP Operating Temperature VACUUM 3 24 In Hg ai EN mss MILEAGE 55011 When the Feedback Fuel Control System controls fuel mixture properly the injector on time will modulate from about 1 6 ms at idle to about 6 35 ms under cold cranking or Wide Open Throttle WOT operation The injector coil release spike s ranges are from 30 V to 100 V normally The turn off spikes less than 30 V may indicate shorted injector coil Initial drive voltage should go close to 0 V If not injector driver may be weak Troubleshooting Tips Spikes during on time or unusual high turn off spikes indicate the injector driver s malfunction On GM and some ISUZU dual TBI systems lots of extra oscillations or hash in be
64. ature VACUUM 20 In Hg MILEAGE 123686 ov Aua BAV mMm Normal voltage ranges are about 0 8 V to 2 0 V above the static battery voltage with the Key Off Engine Off Over 2 0 V may indicate an overcharge condition and less than 0 8 V may indicate an undercharge solution Different vehicles have different charging system specifications Consult the manufacturer s specs General rules of thumb GM 14 5 to 15 4 V Ford 14 4 to 14 8 V and Chrysler 13 3 to 13 9 V IMPORTANT The test results can be different in a big way according to the ambient temperature what electrical loads are on the battery during testing the age of battery the battery s charging state the level and quality of the battery s electrolyte or the battery design Troubleshooting Tips If the output voltage is excessively high or the battery is leaking wet smells like acid or is boiling the alternator may be defective Check the regulator for its proper operation Also perform a voltage drop test on both sides of the alternator housing and at the battery If the voltage is different the alternator may be grounded improperly 6 52 Alternator Field VR Voltage Reference e Theory of Operation A voltage regulator in the PCM controls alternator output by adjusting the amount of current flowing through the rotor field windings To increase alternator output the voltage regulator allows more current to flow through the rotor field windings The field c
65. ck carburetor systems operate in the same way more mixture control on time means lean mixture command Generally mixture control commands from the PCM that oscillate around duty cydes greater than 50 mean the system is commanding a lean mixture in an effort to compensate for a long term rich condition Symptoms Hesitation on throttle tip in poor fuel economy erratic idle rich or lean emissions Test Procedure IMPORTANT Before performing the test procedure the sensor must be tested and confirmed good 1 Connect the CH A lead to the mixture solenoid control signal from the PCM and its ground lead to GND 6 39 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System enters closed loop Verify this by viewing the O2 sensor signal 3 Shut off A C and all other accessories Put vehicle in park or neutral Adjust lean stop air bleed and idle mixture as per recommended service procedures for the carburetor being serviced 4 Use the Glitch Snare mode the check for signal dropouts Reference Waveform VEHICLE INFORMATIONS NOTE Ozsensor YEAR 1984 MAX 31 6 TuS De 9009 10 MAKE Oldsmobile i i MODEL Delta 88 i i ENGINE 5 0L 18 t lie Ht FUELSYS Feedback Carburetor LET aiai PCM_PIN 18 Blu wire at test connector STATUS KOER Key On Running i RPM Idle ov S nahii iaa ENG_TMP Operating Temperature VACUUM 19
66. d safety procedures and the safety precautions specified in this manual A DANGER identifies an imminently hazardous situation which if not avoided will result in death or serious injury to the user or the bystanders A WARNING identifies conditions and actions that pose hazard s to the user or the bystanders A CAUTION identifies conditions and actions that may damage the instrument or the vehicle The term Isolated or Electrically floating is used in this manual to indicate a measurement in which the COM terminal of this instrument is connected to a voltage different from earth ground The term Grounded is used when the COM terminal is connected to an earth ground potential The COM terminal of this instrument is rated up to 300 V rms above earth ground for the safety of isolated measurements Using Your Instrument Safely Follow safe servicing practices as described in your vehicle service manual To use this instrument safely follow the safety guidelines below A DANGER e Use the instrument in service area WELL VENTILATED providing at least four change of air per hour Engines produce carbon monoxide an odorless colorless and poisonous gas that causes slower action time and can result in death or serious injury Route exhaust outside while testing with engine running e Set the parking brake and block the wheels especially the wheels on front wheel drive vehicles before testing or repairing the vehicle because the
67. d circuits SCOPE Use Single Input Scope mode if you want to measure a single signal INPUT B is turned off Use Dual Input Scope mode if you want to simultaneously measure two waveforms one on INPUT A and the other on INPUT B GRAPHING MULTIMETER INPUT A is used for all GMM Graphing Multimeter tests The probes and test leads to be used depend upon the type of test performed VEHICLE DATA Set the vehicle data to match the vehicle under test If they do not match you could get incorrect test results and may not be able to select all available tests for this vehicle This menu appears at power on as the start up display due to its importance INSTRUMENT SETUP Use this menu option to set the following e Optimal settings for display e Filter function enabled and disabled e Auto Power Off enabled and disabled and adjusting the Auto Power Off time e Language for menus and HELP text e Version Information of current software Scope Calibration when using the scope in abnormal operating environments Menu Overview Figure 6 shows an overview of available test functions displays and setups from the MENU key The MAIN MENU choices represent categories of applications that are listed in sub menus as shown in the following figure 4 10 FILTER MENU INPUT A OFF FILTER INPUT B OFF MAIN MENU COMPONENT TESTS SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP GRAPHING MULTIMETER MENU VOLT DC AC OHM DIODE CO
68. d valve via a pulse width modulated signal Symptoms Poor driveability engine damage blown head gasket hard stall under acceleration Test Procedure 1 Connect the CH A lead to the solenoid control signal from the PCM and its ground lead to the chassis GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel system enters closed loop Verify this by viewing the Oz sensor signal if necessary 3 Drive the vehicle as needed to make the suspected problem occur 4 Make sure that the drive signal comes on as the boost pressure is regulated and the wastegate actually responds to the solenoid control signal Reference Waveform VEHICLE INFORMATIONS Bede m Hz h 3 a i YEAR 1988 MAX 28 0 yv i i MAKE x Chrysler 20V H i BEE MODEL LeBaron Convertible US et ENGINE 2 2L Turbo t N AEN AA E M A A ANAR lest FUELSYS Multiport Fuel Injection J PCM_PIN 39 LtGrn Blk wire STATUS KOBD Key On Driven Ov iar a a aici r RPM Moderate Acceleration 35 MPH ENG_TMP Operating Temperature VACUUM 5 In Hg SV Auin w BNV athe MILEAGE 77008 As soonas the turbo engine reaches a predetermined boost pressure under acceleration the PCM should begin pulsing the turbo boost solenoid with a varying pulse width modulated signal to open the wastegate On deceleration the signal is stopped and the valve is closed Troublesho
69. damaged Select the proper function and range for your measurement e When using the probes keep your fingers away from probe contacts Keep your fingers behind the finger guards on the probes 2 2 Disconnect the live test lead before disconnecting the common test lead Do not perform internal service or adjustment of this instrument unless you are qualified to do so Avoid Burns Do not touch hot exhaust systems manifolds engines radiators sample probe etc Do not remove radiator cap unless engine is cold Pressurized engine coolant may be hot Wear gloves when handling hot engine components e Use a suitable battery carrier when transporting batteries ZS CAUTION e Disconnect circuit power and discharge all high voltage capacitors before connecting the instrument to make resistance continuity or diodes measurements Do not rely on questionable erratic or obviously erroneous test informations or results Make sure that all connections and data entry information are correct and that the test procedure was taken correctly Do not use suspicious test information or results for diagnostics DECLARATION OF CONFORMITY for FINEST 1005 Automotive Scope GMM Manufacturer Fine Instruments Corporation 341 5 Songnae Dong Sosa Gu Bucheon Kyunggi Do Republic of Korea Statement of Conformity Based on test results using appropriate standards the product is in conformity with Electromagnetic Compatibility Directiv
70. dback system Continuity Instrument setup to check wiring circuits connectors or switches for breaks open circuit or closed circuits Contrast This setting expressed in a percentage determines the contrast ratio between display text or graphics and the LCD background 0 is all white 100 is all black Conventional Ignition system that uses a distributor Ignition System Cursor A vertical or horizontal line kind of ruler that you can place on the screen and move Function Key Labels Labels shown on the bottom display that indicate the function of the function keys Gp horizontally or vertically to measure values at certain points of the waveform to CFB Direct Current Function Key Menu The function key labels listed on the bottom display DC Coupling A mode of signal transmission that passes both AC and DC signal components to the Glitch A momentary spike in a waveform This can be caused by a momentary disruption in input INPUT A or INPUT B of the instrument the circuit under test Default Setup The setup that exists as long as there are no changes made to the settings Glow plug A combustion chamber heat generating device to aid starting diesel engines Diesel Probe A test probe that has a pickup element to measure the pressure pulse in the diesel fuel Governor A device designed to automatically limit engine speed PRS it converts tuel PIPE expansion Into voltage Ground An electrical conductor used as a common retum for an electr
71. dwell section represents coil saturation which is the period of time the points are closed or the transistor is on The ignition or distributor dwell angle is the number of degrees of distributor rotation during which the points or transistor are closed or magnetic saturation time in degrees Normally it takes about 10 to 15 ms for an ignition coil to develop complete magnetic saturation from primary current The secondary ignition test has been an effective driveability check for over three decades along with the primary ignition test The ignition secondary waveform can be useful in detection of problems in mechanical components of engine and fuel system as well as the ignition system components When the PARADE mode is selected this instrument will present a parade of all the cylinders starting at the left with the spark line of the number 1 cylinder The instrument will display the pattern for each cylinder s ignition cycle in the engine s firing order For example if the firing order fora given engine is 1 4 3 2 the instrument will display the ignition cycles for each cylinder as shown starting with cylinder number 1 then 4 then 3 and then 2 6 61 Firing lines should be equal A short line indicates low resistance in the wire A high Firing lines clearly displayed line indicates high resistance in the wire for easy comparison Available voltage should be about 10 kV on a conventional ignition system and even greater with a
72. e 89 336 EEC Low Voltage Directive 73 23 EEC Sample tests Standards used EN 61010 1 A2 1995 amp EN 61010 2 031 1994 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use EN 61326 1997 A A 1998 Electromagnetic Compatibility Generic Emission amp Immunity Standard The tests have been performed by TUV PRODUCT SERVICE GMBH This Conformity is indicated by the symbol CE i e Conformit Europ enne 3 AUTOMOTIVE ELECTRONIC SIGNALS 3 1 PRIMARY SIGNAL TYPES FOUND IN MODERN VEHICLES Once you become familiar with basic vehicle waveforms it will not matter how new or old the vehicle is or even who manufactured the vehicle You will be able to recognize signals that do not look right Direct Current DC Signals The types of sensors or devices in a vehicle that produce DC signals are e Power Supplies Battery voltage or sensor reference voltages created by the PCM Analog sensor signals engine coolant temperature fuel temperature intake air temperature throttle position EGR pressure and valve position oxygen vane and hot wire mass airflow sensors vacuum and throttle switches and GM Chrysler and Asian manifold absolute pressure MAP sensors Alternating Current AC Signals The types of sensors or devices in a vehicle that produce AC signals are e Vehicle speed sensors VSS Antilock brake system wheel speed sensors ABS wheel speed sensors Magnetic camshaft CM
73. e abrasives solvents or alcohol Do not use any type of paper to clean the display screen This will cause scratches and diminish the transparency of the screen Use only a soft cloth with a mild detergent Keeping Batteries in Optimal Condition Always operate the instrument on batteries until a battery symbol __ appears in the top right of the display This indicates that the battery level is too low and the batteries need to be recharged AS CAUTION Frequent charging of the batteries when they are not completely empty can cause a memory effect This means that the capacity of the Ni MH batteries decreases which can reduce the operating time of the instrument Replacing and Disposing of Batteries AN WARNING To avoid electrical shock remove the test leads probes and battery charger before replacing the batteries 1 Disconnect the test leads probes and battery charger from both the source and the instrument 2 Remove the battery cover by using a screwdriver 3 Replace the Ni MH battery pack with a new Ni MH battery pack ONLY specified in this manual 4 Reinstall the battery cover by using a screwdriver amp NOTE Mr Do not dispose of the replaced battery with other solid waste Used batteries should be disposed of by a qualified recycler or hazardous materials handler Fuses Not Required Since the instrument uses electronically protected inputs no fuses are required 7 1 8 Specifications General Specifications Opera
74. e active function Pressing F4 CLOSE CONTINUITY becomes the active function CONTINUTY 4 13 KEYS PRANGE A KEYS CURSOR 1 CURSOR 2 REPEAT TEST INVERT GMM MODE SCOPE MODE GLITCH SNARE The KEYS icon indicates that you can use the Four Way arrow keys to change Volt amp Time ranges to move the waveform position and to adjust the trigger level for either INPUT A or INPUT B And also you can use the Four Way arrow keys to adjust the sensitivity level in the COMPONENT TEST IGNITION mode Press F5 to toggle among IGYANCIWN EONS and EAA for INPUT A or among ae M S and Mieg for INPUT B The icon indicates that you can use the Four Way arrow keys to move CURSOR 1 if Kelto is highlighted or move CURSOR 2 if elst e i 4 is highlighted Press the function key to toggle between CURSOR 1 and CURSOR 2 This Label is displayed for SINGLE DISPLAY tests for example the knock sensor test To repeat the test press the function key then perform the required action The knock sensor test is a single shot measurement which means that the signal from the knock sensor is displayed only once To get a new test result you have to press the F3 key and then tap the engine block or the sensor again You may have to readjust the vertical RANGE to get an optimal waveform To change to the opposite polarity Puts the waveform display upside down This Label is displayed in the Scope test mode of the
75. e ground level This could indicate a high resistance or bad ground supply to the sensor Although the Hall CKP sensors are generally designed to operate in temperatures up to 318 F 150 C they can fail at certain temperatures cold or hot Optical CranKshaft Position CKP Sensor e Theory of Operation These CKP sensors are classified as CKP Sensors High Resolution in industry The optical CKP sensors can sense position of a rotating component even without the engine running and their pulse amplitude remains constant with variations in speed They are not affected by electromagnetic interference EMI They are used to switch the ignition and or fuel injection triggering circuits on and off The optical sensor consists of a rotating disk with slots in it two fiber optic light pipes an LED and a phototransistor as the light sensor An amplifier is coupled to the phototransistor to create a strong enough signal for use by other electronic devices such as PCM or ignition module The phototransistor and amplifier create a digital output signal on off pulse e Symptoms OBD II DTC s P0340 P0349 P0365 P0369 P0390 P0394 No or hard starts stall at stops misfires poor fuel economy emissions failure Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With KOER Key On Engine Running let the engine idle or use the throttle to accelerate
76. e number of acquisitions performed per second Actuator A mechanism for moving or controlling something indirectly instead of by hand Alternating Current An electrical signal in which current and voltage vary in a repeating pattern over time Alternator An AC generator with diode rectification Amplitude The difference between the highest and the lowest level of a waveform Attenuation The decrease in amplitude of a signal Auto Range Activates an automatic adaptation of the instrument to the input signal in amplitude timebase and triggering Bandwidth Baud Rate Blower A frequency range Communication parameter that indicates the data transfer rate in bits per second A device designed to supply a current of air at a moderate pressure The blower case is usually designed as part of a ventilation system BNC Bottom Display Zz Coaxial type input connector used for INPUT A and INPUT B The lower part of the display where the function key menu is listed Bypass Providing a secondary path to relieve pressure in the primary passage Carburetor A mechanism which automatically mixes fuel with air in the proper proportions to provide a desired power output from a spark ignition internal combustion engine Catalytic Converter An in line exhaust system device used to reduce the level of engine exhaust emissions Closed Loop Engine An operating condition or mode which enables modification of programmed instructions based on a fee
77. eally want to see in DC circuits such as power distribution If noise is obscuring the signals you want to see try the following tips Using the Internal Battery Power In general noise pickup is minimized when you use this instrument on its internal battery power Using the standard Shielded Test Leads supplied will help in noise rejection Noise Filter Turn on the Filter INSTRUMENT SETUP menu for the input channel you are using This blocks frequencies above 2 kHz and should reduce ignition impulse noises and other noises of the short spike variety Ground Connections Many sensors output signals are single ended meaning that a single output pin delivers the signal with being referred to a ground pin also on the sensor In order for the signal to be accurately delivered to the PCM however both the signal and ground parts of the circuit should be sound If a sensor output signal at the PCM appears to be erratic or its level appears incorrect check the signal at the output pins of the sensor both signal and ground connections If the signal is correct suspect the wire hamess of either the signal or the ground side Check for voltage drops in both the signal and the ground paths between the sensor and the PCM Never trust that a chassis ground connection is the same as the PCM or the sensor ground The ground continuity can be disrupted by a missing strap or loose fastener easily 6 AUTOMOTIVE DIAGNOSTICS amp APPLICA
78. ent on The instrument beeps once and turns on At power on the instrument displays the VEHICLE DATA menu as shown in Figure 1 VEHICLE DATA MENU EERE Default settings CYCLES 4 You can change the BATTERY 12V settings to match with the vehicle under test IGNITION CONV Press the F1 key to Press the F5 key to accept the displayed change the highlighted tings lection settings ae CBS selectio Figure 1 Vehicle Data Menu at Power On Changing the Power On Display Use Instrument Setup menu option to change the Power On display from VEHICLE DATA MENU default to the user s last display Resetting the Instrument If you want to restore the instrument settings as delivered from the factory do the following 1 Turn the instrument off by pressing the POWER key 2 Keep F5 depressed while you turn the instrument on by pressing the POWER key Release F5 You will hear a double beep to indicate that the Master Reset has been executed NOTE The Master Reset clears all memory data Performing a Navigation Exercise To display the MAIN MENU while a measurement display is active press the MENU key to display the MAIN MENU as shown in Figure 2 This menu lists all of the tests displays and setups available e COMPONENT TESTS e SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP The fastest way to set up the instrument to test most automotive devices sensors actuators and circuits is to choose fr
79. erate and decelerate the engine Try different RPM ranges while spending more time in the RPM ranges that correspond to the driveability problem 3 Make sure that the amplitude frequency and shape are all correct consistent and repeatable 4 Make sure that the sensor generates the correct frequency for a given RPM or airflow rate 5 Use the Glitch Snare mode to detect dropouts or unstable output frequency 6 27 Reference Waveform VEHICLE INFORMATIONS ex eae YEAR 1986 MIN 0 00 V MAKE Oldsmobile MODEL Toronado ENGINE 3 8L FUELSYS Multiport Fuel Injection PCM_PIN B6 Yel wire STATUS KOER Key On Running RPM Snap Acceleration Idle air flow here Eme ENG_TMP Operating Temperature before snap accel VACUUM 0 24 In Hg MILEAGE 123686 Frequency stays constant when airflow is constant Frequency increases as airflow increases from snap acceleration Look for pulses that are a full 5 V in amplitude Voltage transitions should be straight and vertical Voltage drop to ground should not exceed 400 mV If greater than 400 mV look for a bad ground at the sensor or the PCM Troubleshooting Tips Possible defects to watch for are runted shortened pulses unwanted spikes and rounded off corners that could all have the effect of garbling an electronic communication causing a driveability or emissions problem The sensor should be replaced if it has intermittent faults Digital Fast MAF Mass Air Flo
80. esolution 0 001 V 0 01 V 0 5 50 600 V gt Input Impedance 10 MQ 25 50 AC DC Voltage Measurement a angs solution 40 Hz 400 Hz 400 Hz 10 kHz DC 500 mV DC5V 0 001 V 0 8 5d 3 0 5d DC 50 V 0 01 V DC 600 V RPM Measurement 4 cylinder 120 20000 RPM 2 RPM 2 cylinder 60 10000 RPM Frequency Measurement s01 30 Te m 20 08 Ohm Measurement 0 5 50 5M 0 001 M 0 75 50 0 01 M 0 75 10d Continuity Test Repro TO Diode Test Temperature Measurement 50 C to 1300 C 0 1 C 58 F to 2372 F 0 1 F 2 0 5 d 3 C 5 4 F DC Ampere Measurement Current Probe Output Accuracy 1 5 20 mA 2 0 20 mA 4 0 0 3 A AC Ampere Measurement Current Probe Output 30 mA 10A 1 mV 10 mA 100 mA 40 A 1 mV 100 mA 40A 60A 1 mV 100 mA 40 Hz 1 kHz 1 kHz 5 kHz 2 0 20 mA 4 0 30 mA 2 0 20 mA 6 0 30 mA 8 0 0 3 A GLOSSARY Terminology Description Antilock Brake System n gt O Alternating Current AC Coupling A mode of signal transmission that passes the dynamic AC signal component to the input INPUT A or INPUT B but blocks the DC component Useful to observe an AC signal that is normally riding on a DC signal e g charging ripple Acquisition The process of gathering measurement data into the instrument s memory Acquisition Rate Th
81. f Use DUAL INPUT SCOPE mode if you want to simultaneously measure two signals OTN MENU NX Function keys and Result Screen HOLD gt SCOPE FILTER AUTO RACANANAOROMUMNAUAIZ Figure 12 Scope Display Automatic ranging and signal tracking is on Pressing mno sets automatic ranging and signal tracking on and off If on AUTO is displayed if off AUTO is disappeared Trigger level voltage of INPUT A Time base range Trigger icon Indicates trigger slope 4 indicated negative slope Auto triggered INPUT A range setting INPUT B range setting Indicates signal source channel A INPUT A zero level Indicates trigger location Indicates signal source channel B INPUT B zero level Making an Easy Setup When you enter the scope mode the instrument automatically optimizes vertical range time base and trigger settings to create a stable display Autoranging is default e When you press one of the Voltage and Time control keys the instrument switches to manual control of range and trigger settings cannot get a stable display using manual control SCOPE displays are defaulted in Glitch Detection mode This means that all signals are sampled at the full sample rate of the instrument and the minimum and maximum excursions are always shown on the display even if the horizontal time setting is too slow to show each individual sample interval I
82. f this also displays OFL the diode is defective A good diode must display OFL when connected in reverse Measuring RPM The instrument automatically scales and displays the waveform on the screen Connect the Inductive Pickup to the COM TRIGGER input terminals and clamp the pickup probe on the spark plug wire close to the spark plug GMM RPM Press to adjust the built in pow trig 4 step trigger levels 2 Press to start plotting a new graph Default is Level 2 FN CD CED CD CED as new samples are acquired Press to restore the default value settings stored in VEHICLE DATA Press to increase n DEFAULT REPEAT 7 t SETUP TEST Press to decrease CF2 and F3 keys are used to set the number of Spark Signal Pulses to the instrument per 720 two crank shaft revolutions n 1 2 3 4 5 6 8 10 or 12 Testing Frequency Duty Cycle or Pulse Width GRAPHING MULTIMETER FREQUENCY DUTY CYCLE PULSE WIDTH GMM FREQUENCY GMM DUTY CYCLE GMM PULSE WIDTH areca elm tefat Shae el a ap Cre CR CFA CFD Press to test the signal frequency in Hz CF ce CD Cra CED Press to test the duty cycle of the signal If you select 4 the duty cycle of the negative going pulse is displayed If you select the duty cycle of the positive going pulse is displayed Testing Secondary Ignition Peak Volts Burn Volts and Burn Time ie MENU GMM IGNITION PEAK VOLTS GRAPHING MULTIMETER G
83. g Tips Check the manufacturer s specifications for exact voltage range specifications but generally the sensor s voltage should range from 3 V to just under 5 V when stone cold dropping to around 1 to 2 V at operating temperature The good sensor must generate a signal with a certain amplitude at any given temperature Opens in the FT sensor circuit will appear as upward spikes to V Ref Shorts to ground in the FT sensor circuit will appear as downward spikes to ground level INTAKE AIR TEMP IAT Sensor e Theory of Operation Most Intake Air Temperature IAT sensors are Negative Temperature Coefficient NTC type thermistors They are primarily two wire analog sensors whose resistance decreases when their temperature increases They are supplied with a 5 V V Ref power signal and return a voltage signal proportional to the intake air temperature to the PCM Some sensors use their own case as a ground so they have only one wire the signal wire When this instrument is connected to the signal from an IAT sensor what is being read is the voltage drop across the sensor s NTC resistor Typically IAT sensor s resistance ranges from about 100 000 ohms at 40 F 40 C to about 50 ohms at 266 F 130 C 6 8 e Symptoms OBD II DTC s P0110 P0114 Poor fuel economy hard start high emissions tip in hesitation e Test Procedure 1 Backprobe the terminals on the IAT sensor with the CH A lead and its ground lead 2 Whe
84. gnition timing bad injector fouled spark plug or other causes Longer burn lines over 2 ms can indicate an abnormally rich mixture and shorter burn line under 0 75 ms can indicate an abnormally lean mixture Look for at least 2 preferably more than 3 oscillations after the burn line This indicates a good ignition coil and a good condenser on point type ignitions DI Distributor Ignition Secondary Conventional Single and Parade Secondary ignition patterns are very useful when diagnosing ignition related malfunctions The secondary scope pattern is divided into three sections of Firing Line spark initiated Points close or transistor turns ON Points open or transistor turns OFF Spark Line or Burn Line Spark is extinguished Coil oscillations amp 4 j Dwell Section 1 Firing Intermediate Section Section SECONDARY FIRING SECTION The firing section consists of a firing line and a spark or burn line The firing line is a vertical line that represents the voltage required to overcome the gap of the spark plug The spark line is a semi horizontal line that represents the voltage required to maintain current flow across the spark gap SECONDARY INTERMEDIATE SECTION The intermediate section displays the remaining coil energy as it dissipates itself by oscillating between the primary and secondary side of the coil with the points open or transistor off SECONDARY DWELL SECTION The
85. gnitions DIS Distributorless Ignition System Secondary e Theory of Operation Most Distributorless Ignition systems use a waste spark method of spark distribution Each cylinder is paired with the cylinder opposite to it 1 4 or 3 6 or 2 5 The spark occurs simultaneously in the cylinder coming up on the compression stroke and in the cylinder coming up on the exhaust stroke The cylinder on the exhaust stroke requires very little of the available energy to fire the spark plug The remaining energy is used as required by the cylinder on the compression stroke The same process is repeated when the cylinders reverse roles 6 65 The secondary POWER WASTE spark display waveform can be used to test several aspects of El or DIS system operation This test can be used to 1 analyze individual cylinder dwell coil charging time 2 analyze ignition coil and secondary circuit performance from the firing line 3 locate incorrect air fuel ratio in individual cylinders from the burn line and 4 locate fouled or damaged spark plugs that cause a cylinder misfire from the burn line Generally on modern high energy ignition HEI systems firing voltages should be around 15 kV to beyond 30 kV Firing voltages vary based on spark plug gap engine compression ratio and air fuel mixture On dual spark El systems the WASTE spark is usually much lower in peak voltage than the POWER spark Close to 5 kV can be normal Symptoms No or
86. ially depending on vehicle engine families in some cases this sensor can be difficult to diagnose definitively Digital Slow MAF Mass Air Flow Sensor e Theory of Operation There are three main varieties of digital MAF sensors Digital Slow type output signals in the 30 to 500 Hz range Digital Fast type output signals in the kHz range and Karman Vortex type which changes pulse width as well as frequency A digital MAF sensor receives a 5 V reference signal from the PCM and sends back a variable frequency signal that is proportional to the mass of air entering the engine The output signal is a square wave in most cases with a full 5 V in amplitude As the airflow increases the frequency of the signal generated increases The PCM uses these signals to calculate fuel injector ON time and ignition timing and also determines MAF sensor deterioration by comparing the MAF signal to a calculated value based on MAP TP IAT and RPM signals Digital Sow MAF sensors can be found on early to mid 1980 s GM vehicles and many other engine systems Generally the older the MAF sensor the slower the frequency it produces e Symptoms OBD II DTC s P0100 P0104 Hesitation stall low power idle problems excessive fuel consumption emissions failure Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With the Key On Engine Running KOER use the throttle to accel
87. ic circuit s and with a Differential Measurement of the difference between the waveform sample values at the positions of relative zero potential Measurement Delta the two cursors Ground Controlled A circuit that is energized by applying ground voltage has been already supplied Diode An electrical device that allows current to flow in one direction only Circuit Direct Current A signal with constant voltage and current Hall Effect Sensor A semiconductor moving relative to a magnetic field generating a variable voltage DIS Distributorless Ignition System or Hall Sensor output Used to determine position in the automotive industry Division A specific segment of a waveform as defined by the grid on the display Rotational speed of an engine with vehicle at rest and accelerator pedal not depressed go O For example when you turn off the current through a solenoid a voltage spike is Drive A device which provides a fixed increase or decrease ratio of relative rotation between Ignition System used to provide high voltage spark for internal combustion engines its input and output shafts Inductance The signal caused by a sudden change of a magnetic field Driver A switched electronic device that controls output state Duty Cycle Cisfime oro tie to period Ume Tale expressed Ina percentage Intake Air Air drawn through a cleaner and distributed to each cylinder for use in combustion generated across the solenoid EIA 232 D RS 232C Internation
88. ifold EGR valve and vacuum solenoid valve are intact and routed properly with no leaks Make sure the EGR valve diaphragm can hold the proper amount of vacuum check manufacturer s specs Make sure that the EGR passageways in and around the engine are clear and unrestricted from internal carbon buildup 6 Press the HOLD key to freeze the waveform on the display for closer inspection 6 31 e Reference Waveform VEHICLE INFORMATIONS MAX 1 86 V i YEAR 1994 A MAKE Ford Ford EGR Differential Pressure Sensor logged during snap MODEL Explorer acceleration ENGINE 4 0L aV i i FUELSYS Multiport Fuel Injection PCM_PIN 27 BrnLtGrn wire PA We et STATUS KOER Key On Running v RPM Snap Acceleration j Enone ee fa ENG_TMP Operating Temperature VACUUM 3 24 In Hg 1 mie oan ia MILEAGE 40045 As soon as the engine reaches the predetermined EGR requirement conditions the PCM will begin opening the EGR valve The waveform should rise when the engine is accelerated The waveform should fall when the EGR valve closes and the engine decelerates EGR demands are especially high during accelerations During idle and deceleration the valve is closed e Troubleshooting Tips There should be no breaks spikes to ground or dropouts in the waveform 6 3 ACTUATOR TESTS we MENU ACTUATOR TESTS MENU Injector PFI MFI COMPONENT TESTS Injector TBI Injector PNP ACTUATORS Injector Bosch
89. ightly and watch for the corresponding injector on time increase on acceleration 1 Induce propane into the intake and drive the mixture rich If the system is working properly the injector on time will decrease 2 Create a Vacuum leak and drive the mixture lean The injector on time will increase 3 Raise the engine to 2500 RPM and hold it steady The injector on time will modulate from slightly larger to slightly smaller as the system control the mixture Generally the injector on time only has to change from 0 25 ms to 0 5 ms to drive the system through its normal full rich to full lean range IMPORTANT If the injector on time is not changing either the system may be operating in an open loop idle mode or the O2 sensor may be bad 4 Use the Glitch Snare mode to check for sudden changes in the injector on time 6 36 e Reference Waveform VEHICLE INFORMATIONS MAX 15 9V PCM Tera en YEAR _ 1990 DUR 6 07 ms MAKE Jeep 10V i MODEL Cherokee ov ENGINE 4 0L i FUELSYS Multiport Fuel Injection POM Ime PCM_PIN 4 Yel wire at 4 injector py sich STATUS KOER Key On Running bard L_power on f RPM Idle i ENG_TMP Operating Temperature VACUUM 16 5 In Hg 100 AN da MILEAGE 85716 When the Feedback Fuel Control System controls fuel mixture properly the injector on time will modulate from about 1 6 ms at idle to about 6 35 ms under cold cranking or Wide Open Throttle WOT operation The
90. in the injector on time 6 38 e Reference Waveform VEHICLE INFORMATIONS MAX 50 6 V t MIN 3 33 V E YEAR 1986 DUR T223 mE MAKE Nissan Datsun A a MODEL Stanza Wagon ENGINE 2 0L FUELSYS Multiport Fuel Injection PCM_PIN B WhtBik wire STATUS KOER Key On Running RPM Idle ENG_TMP Operating Temperature VACUUM 21 In Hg rig ee i Wee ms MILEAGE 183513 When the Feedback Fuel Control System controls fuel mixture properly the injector on time will modulate from about 1 6 ms at idle to about 6 35 ms under cold cranking or Wide Open Throttle WOT operation The injector coil release spike s ranges are from 30 V to 100 V normally IMPORTANT On some European vehicles like Jaguar there may be only one release spike because the first release spike does not appear due to a spike suppression diode Troubleshooting Tips Spikes during on time or unusual high turn off spikes indicate the injector driver s malfunction Mixture Control Solenoid Theory of Operation The mixture control signal is the most important output signal in a carbureted Feedback Fuel Control system On a GM vehicle this circuit pulses about 10 times per second with each individual pulse pulse width or on time varing depending upon the fuel mixture needed at that moment In a GM vehicle this circuit controls how long per pulse the main jet metering rods in the carburetor stay down lean position Most feedba
91. indicate a high resistance or bad ground supply to the sensor Although the Hall CMP sensors are generally designed to operate in temperatures up to 318 F 150 C they can fail at certain temperatures cold or hot Optical Camshaft Position CMP Sensor 6 18 e Theory of Operation These CMP sensors are classified as CMP Sensors High Resolution in industry The optical CMP sensors are high resolution accuracy digital sensors which generate the CMP signal that is a high frequency hundreds of Hz to several kHz square wave switching between zero and V Ref The optical CMP sensors can sense position of a rotating component even without the engine running and their pulse amplitude remains constant with variations in speed They are not affected by electromagnetic interference EMI They are used to switch the ignition and or fuel injection triggering circuits on and off The optical sensor consists of a rotating disk with slots in it two fiber optic light pipes and LED and a phototransistor as the light sensor An amplifier is coupled to the phototransistor to create a strong enough signal for use by other electronic devices such as PCM or ignition module The phototransistor and amplifier create a digital output signal on off pulse e Symptoms OBD II DTC s P0340 P0349 P0365 P0369 P0390 P0394 No or hard starts stall at stops misfires poor fuel economy emissions failure Test Procedure 1 Connect the C
92. ine Ford s IAC solenoids are driven by a DC signal with some AC superimposed on top The solenoid opens the throttle plate in proportion to the DC drive it receives from the PCM The DC drive is applied by holding one end of the solenoid coil at battery positive while pulling the other end toward GND The DC voltage at the driven pin decreases as the solenoid drive current is increased e Symptoms Erratic high or low idle stalling high activity but no change in idle Test Procedure 1 Connect the CH A lead to the IAC control signal from the PCM and its ground lead to the chassis GND 2 Run the engine at idle while turning accessories A C blowers wipers etc on and off If the vehicle has an automatic transmission put it in and out of drive and park This will change the load on the engine and cause the PCM to change the output command signal to the IAC solenoid 3 Make sure that the amplitude frequency and shape are all correct repeatable and consistent for the various idle compensation modes 4 Make sure that idle speed responds to the changes in the IAC drive 6 43 Reference Waveform VEHICLE INFORMATIONS FREQ 158 H 3 MAX 12 2V YEAR 1993 MIN 6 40 V MAKE Ford MODEL Explorer 15V i i ENGINE 4 0L MAT he eth AL FUELSYS Multiport Fuel Injection N N Yi NI Y uy N PCM_PIN 21 Wht LtBlu wire STATUS KOER Key On Running S RPM Idle i ENG_TMP Operating Temperature VACUUM 19 In Hg id Aa f
93. ing Sample acquisition intervals 480 e Sample points Normal mode acquires a single sample point in each interval The maximum sample rate is 25 MS s At 10 us and faster settings this sample rate does not acquire 480 points In this case a Digital Signal Processor interpolates points between the sampled points to make a full 480 point waveform record FILTER MENU Can be set On or Off default is Off for each INPUT e Off Passes all signal components up to 5 MHz On Passes signal components up to 2 KHz Turn on this option to reduce noises in scope displays and measurements AUTO POWER OFF MENU AUTO POWER OFF You can adjust the Auto Power Off time between 5 minutes and 120 minutes LANGUAGE MENU LANGUAGE This setting is used to select the local language or English for the information text display This option is not available if only one language is implemented VERSION INFORMATION MENU VERSION INFORMATION You can see the version number of current software SCOPE CALIBRATION MENU SCOPE CALIBRATION This setting is used to minutely calibrate the scope under the following operating environments e When measuring in extremely hot or cold places e When the inner temperature of the scope was increased very greatly due to its long operation Press F5 when SCOPE CALIBRATION is highlighted to activate this setting 5 6 FREEZING SAVING AND RECALLING SCREENS Hold Mode The HOLD key enables you to freeze the cu
94. int type ignitions 6 67 6 6 DIESEL TESTS ie VEHICLE DATA IGNITION The diesel test functions are selected if IGNITION DIESEL has been set in the VEHICLE DATA menu To choose a preset DIESEL test menu select COMPONENT TESTS from the MAIN MENU From the resulting menu select DIESEL TESTS menu COMPONENT TESTS DIESEL TEST MENU CESES DIESEL INJECTOR ADVANCE Introduction During the compression stroke of a diesel engine the intake air is compressed to about 735 psi 50 Bar The temperature hereby increases up to 1 292 to 1 652 F 700 to 900 C This temperature is sufficient to cause automatic ignition of the Diesel fuel which is injected into the cylinder shortly before the end of the compression stroke and very near to the TDC Top Dead Center Diesel fuel is delivered to the individual cylinders at a pressure of between 5145 psi and 17 640 psi 350 Bar and 1200 Bar The start of the injection cycle should be timed within 1 Crankshaft to achieve the optimum trade off between engine fuel consumption and combustion noise knock A timing device controls the start of the injection and will also compensate for the propagation times in the fuel delivery lines Diesel RPM measurements are necessary for adjusting idle speed checking maximum RPM and performing smoke tests at fixed RPM values Measurement Conditions Cleaning The fuel lines to be measured on should be cleaned in order to
95. ion of SPOUT upper trace with respect to PIP lower trace The notches out of the top and bottom comer of PIP go away when the SPOUT connector is removed because this cuts off the TFI s ability to encode the PIP signal with the SPOUT information Troubleshooting Tips If changing manifold vacuum has no effect on the rising edges of SPOUT check for a faulty BP MAP sensor If PIP is absent the engine will not start check for a bad TFI module or other distributor problem lf SPOUT is absent the system may be in LOS Limited Operation Strategy or limp home mode Check for problems in the PCM or bad wiring harness connectors If the rising edges of PIP or SPOUT are rounded timing will be inaccurate although the system may not set an error code Check for problems in the module producing each signal DI Distributor Ignition Primary Theory of Operation The ignition coil primary signal is one of the top three most important diagnostic signals in powertrain management systems This signal can be used for diagnosing the driveability problems such as no starts stalls at idle or while driving misfires hesitation cuts out while driving etc The waveform displayed from the ignition primary circuit is very useful because occurrencies in the ignition secondary burn are induced back into the primary through mutual induction of the primary and secondary windings This test can provide valuable information about the quality of combus
96. ions test failure low power on acceleration e Test Procedure 1 Connect the CH A lead to the injector control signal from the PCM and its ground lead to the injector GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System enters closed loop Verify this by viewing the O2 sensor signal if necessary 3 Shut off A C and all other accessories Put vehicle in park or neutral Rev the engine slightly and watch for the corresponding injector on time increase on acceleration 1 Induce propane into the intake and drive the mixture rich If the system is working properly the injector on time will decrease 2 Create a vacuum leak and drive the mixture lean The injector on time will increase 3 Raise the engine to 2500 RPM and hold it steady The injector on time will modulate from slightly larger to slightly smaller as the system controls the mixture Generally the injector on time only has to change from 0 25 ms to 0 5 ms to drive the system through its normal full rich to full lean range IMPORTANT If the injector on time is not changing either the system may be operating in an open loop idle mode or the O2 sensor may be bad 4 Use the Glitch Snare mode to check for sudden changes in the injector on time 6 33 Reference Waveform VEHICLE INFORMATIONS MAX 35 Lata YEAR 1993 DUR 3 92 ms MAKE Ford 40Y i i MODEL F150 4WD Pickup
97. l FATS torm m us Ravel sian qapay positiv e Slope Be requires the voltage to be increasing as it crosses the Trigger Level a negative Slope original value i requires the voltage to be decreasing ircui I level he vol ff i i 7 Pulse Modulated A circuit that maintains average voltage levels by pulsing the voltage on and o Trigger Source The instrument input that supplies the signal to provide the trigger A manifold for fue injection fuel Transducer A device that receives energy from one system and retransmits transfers it often in a Range Specified limits in which measurements are done different form to another system Reference Voltage An unaltered voltage applied to a circuit Battery plus B and ground GND are For example the cruise control transducer converts a vehicle speed signal to a modulated vacuum output to control a servo examples of reference voltages Regulator Voltage A device that automatically controls the functional output of another device by adjusting Turbocharger Ai centrifugal ac ariveni oy exhaust gases that pressurize the intake ais thereby iP increasing the density of charge air and the consequent power output from a given the voltage to meet a specified value eae engine displacement Relay A generally electromechanical device in which connections in one circuit are opened or closed by changes in another circuit Root Mean Square Conversion of AC voltages to the effective DC value User s Last
98. le assists in making visual voltage and timing measurements The distance between adjacent dots is one division The graticule also allows you to easily compare wave forms between CH A and CH B and stored waveforms for timing and voltage differences HORIZ TRIG POS Horizontal Trigger Position can be set to three different horizontal locations 10 50 or 90 on the display depending on whether you want to see conditions that led up to the trigger event or those following it ACQUIRE MODE Can be set to Peak Detect mode default or Normal mode e Peak Detect This is the default mode to detect glitches and reduces the possibility of aliasing e Normal Use to acquire 480 points and display them at the SEC DIV setting lt Key Points gt If you probe a noisy square wave signal that contains intermittent and narrow glitches the waveform displayed will vary depending on the acquisition mode you choose Normal Peak Detect The next two topics describe each of the types of acquisition modes and their differences Peak Detect Use Peak Detect acquisition mode to detect glitches as narrow as 1 us and to limit the possibility of aliasing This mode is effective when at 10 us div or slower Sampie acquisition intervals 240 ae ae ee ee e Sample points displayed Peak Detect mode displays highest and lowest acquired voltage in each interval Normal Use Normal acquisition mode to acquire 480 points and display them at the SEC DIV sett
99. ll 5 V in amplitude Voltage transitions should be straight and vertical Voltage drop to ground should not exceed 400 mV If the voltage drop is greater than 400 mV look for a bad ground at the sensor or the PCM Troubleshooting Tips A bad digital MAP sensor can produce incorrect frequencies runted shortened pulses unwanted spikes and rounded off corners that could all have the effect of garbling electronic communication thus causing a driveability or emissions problem Analog Mass Air Flow MAF Sensor Theory of Operation There are two main varieties of analog MAF sensors Hot Wire type and Vane type Hot wire type MAF sensors use heated metal foil sensing element to measure air flow entering the intake manifold The sensing element is heated to about 170 F 77 C above the temperature of incoming air As air flows over the sensing element it cools the element causing resistance to drop This causes a corresponding increase in current flow which causes supply voltage to decrease This signal is seen by the PCM as a change in voltage drop high air flow high voltage and is used as an indication of air flow The PCM uses this signal to calculate engine load to determine the right amount of fuel to be mixed with the air and ignition timing EGR control idle control transmission shift points etc 6 25 Vane type MAF sensors mainly consist of a variable resistor potentiometer that tells the PCM the position
100. locate incorrect air fuel ratio in individual cylinders from the burn line and 4 locate fouled or damaged spark plugs that cause a cylinder misfire from the burn line This test can be useful in detection of problems in mechanical engine and fuel system components as well as ignition system components Symptoms No or hard starts stalls misfires hesitation poor fuel economy Test Procedure 1 Connect the CH A lead to the ignition coil primary signal driven side and its ground lead to the chassis GND 2 With the key on engine running let the engine idle or use the throttle to accelerate and decelerate the engine or drive the vehicle as needed to make the driveability problem or misfire occur 3 Make sure that the amplitude frequency shape and pulse width are all consistent from cylinder to cylinder Look for the abnormalities in the section of the waveform that corresponds to specific components 4 If necessary adjust the trigger level for a stable display 6 64 e Reference Waveform VEHICLE INFORMATIONS MAX 170 V a DUR soe YEAR 1994 DWELL 6 00 arc over or MAKE Ford ignition MODEL Explorer voltage ENGINE 4 0L FUELSYS Multiport Fuel Injection PCM_PIN 10 Coil A YelBlk at ignition STATUS KOER Key On Running charging here oscillations ENG_TMP f spark or burn voltage a ren Operating Temperature VACUUM 19 5 In Hg may AA soy ms MILEAGE 40045 The Ignitio
101. ms current 10 mV A and 100 mV A Press to measure AC DC true rms current Don t forget to set the Current Probe to zero before using it for measurements Testing Temperature Use this menu option to test temperature with a temperature probe optional accessory GMM TEMPERATURE Press to select between F Ea measuring degrees Celsius TEST and degrees Fahrenheit Ft C F5 5 4 DUAL INPUT SCOPE OPERATION Dual Input Scope Use the scope function if you want to simultaneously measure two wavefoms one on INPUT A and the other on INPUT B Using Single and Dual Input Scope Use SINGLE INPUT SCOPE if you want to use a single signal INPUT B is turned off Use DUAL INPUT SCOPE if you want to simultaneously measure two signals 5 5 CHANGING THE VEHICLE DATA amp INSTRUMENT SETUP There are two groups of setups in the Main Menu VEHICLE DATA Use this menu option to enter the correct vehicle data such as the number of cylinders or cycles on the vehicle under test 5 13 INSTRUMENT SETUP Use this menu option to set the following e Optimal settings for display e Optimal settings for noise filter to each INPUT e Auto Power Off ON and OFF and adjusting Auto Power Off Time e Language for menus and help text e Scope Calibration Changing Vehicle Data If the vehicle data do not match with the vehicle under test you could get incorrect test results and may not be able to select all available tests for this
102. n Peak voltage and Burn voltage measurements are available in this test but they should be corrected to account for the turns ratio of the coil windings Troubleshooting Tips Look for the drop in the waveform where the ignition coil begins charging to stay relatively consistent which indicates consistent dwell and timing accuracy of individual cylinder Look for a relatively consistent height on the arc over voltage or firing line A line that is too high indicates high resistance in the ignition secondary due to an open or bad spark plug wire or a large spark gap A line that is too short indicates lower than normal resistance in the ignition secondary due to fouled cracked or arcing spark plug wire etc Look for the spark or burn voltage to remain fairly consistent This can be an indicator of air fuel ratio in the cylinder If the mixture is too lean the burn voltage may be higher and if too rich the voltage may be lower than normal Look for the burn line to be fairly clean without a lot of hash which can indicate an ignition misfire in the cylinder due to over advanced ignition timing bad injector fouled spark plug or other causes Longer burn lines over 2 ms can indicate an abnormally rich mixture and shorter burn lines under 0 75 ms can indicate an abnormally lean mixture Look for at least 2 preferably more than 3 oscillations after the burn line This indicate a good ignition coil a good condenser on point type i
103. n electronic system Spark lines can be viewed side by side for ease of comparison Cylinders are displayed in firing order Symptoms No or hard starts stalls misfires hesitation poor fuel economy Test Procedure NOTE A Capacitive type ignition secondary probe must be used to test the ignition secondary circuit Connecting the CH A or CH B leads directly to an ignition secondary circuit can cause severe damage to the instrument or even personal injury Connect the test leads as displayed by the test tool s HELP Test Procedure and shown in Figure below SPARK PLUG SIDE Tr a YA ME arf l N U K Figure Testing Secondary Ignition Conventional Single and Parade 6 62 1 Connect the capacitive type ignition secondary probe to the CH A input terminal and its ground lead to chassis GND 2 Connect the Inductive Pickup to the COM TRIGGER input terminals NOTE The Inductive Pickup must be used to synchronize tiggering between the spark plug wire signal and the coil secondary signal clamped by the capacitive secondary probe 3 Clip the secondary probe to the coil secondary lead wire and clamp the pickup probe on the spark plug wire close to the spark plug IMPORTANT Signals from individual spark plug wires are useful only for triggering Ignition Peak Voltage Burn Voltage and Burn Time measurements may not be accurate if the signal is taken on the spark plug side of the distributor due to the
104. n enable or disable CH A Filter or CH B Filter using the INSTRUMENT SETUP menu When enabled the FILTER indicator appears on the screen Cursor Key Function A cursor is a vertical line or a horizontal line placed over the displayed waveform to measure values at certain points The instrument can measure signal details by using Cursors This function is not possible for all tests Press curso to display the Function key Menu for cursor operation If cursor operation is not possible for the actual measurement the instrument beeps to alert you Two cursors vertical lines appear on the display The left cursor is named CURSOR 1 the right CURSOR 2 CURSOR CURSORS CURSOR KEYS BASK TIME aes CED CF2 CFs e Press C to set TIME cursor or VOLTS cursor or cursor OFF Press F5y to select the cursor you want to move 1 or 2 i Use the Four Way arrow keys to move the cursors The top display shows readings related to values at the cursor positions For TIME cursors TIME 1 20 4 ms DELTA A 48 1 ms TIME 2 68 5 ms Sample value at TIME CURSOR 1 position on the waveform s Sample value at TIME CURSOR 2 position on the waveform s Time difference between TIME CURSOR 1 and TIME CURSOR 2 positions For VOLTS CURSORS Volts difference between CURSOR 1 and Sample value at CURSOR 2 positions on the INPUT A waveform CURSOR 2 position on the INPUT A waveform Sample
105. n if you leave it charging for long periods Typically a 8 hour recharge during instrument working and a 4 hour recharge during instrument off provides the instrument with the maximum use of 4 hours Auto Power Off When operated on batteries no adapter connected the instrument conserves power by turning itself off automatically if you have not pressed a key for 30 minutes or if the battery level is too low The instrument turns back on if the POWER key is pressed The Auto Power Off will be disabled automatically when enters the GMM mode You can adjust the Auto Power Off time between 5 minutes and 120 minutes to use Instrument Setup menu option 4 3 FRONT PANEL CONTROLS Key Conirol Overview Display area for the Function Key Labels Key Descriptions CFL to FS These are the Function keys The function assigned to each key is indicated by the Function Key Label displayed above the key on the bottom display C Displays information about the highlighted menu choice during menu selection Displays information about the function keys when a selected test is running Performs one of the following actions e Moves up and down through menu choices e Moves a waveform up and down Moves a voltage cursor up and down e Adjusts the trigger level when you are in the SCOPE mode Performs one of the following actions e Moves a waveform right and left e Moves a time cursor left and right Ranges amplitude up and
106. n the IAT sensors are at engine operating temperature spray the sensors with a cooling spray a water spray or evaporative solvent spray and monitor the sensor voltage Perform this test with the Key ON Engine Off The waveform should increase in amplitude as the sensor tip cools 3 Press the HOLD key to freeze the waveform on the display for closer inspection 4 To measure resistance disconnect the sensor before changing to the GMM mode and then connect the Ground and CH A leads to the terminals on the sensor Reference Waveform VEHICLE INFORMATION Key On Engine Off YEAR 1986 fee MAKE Oldsmobile i MODEL Toronado gyl ai a a aa aiina a ENGINE 3 8L l t FUELSYS Multiport Fuel Injection RPM 0 ENG_TMP Ambient Temp Intake Air Temp sensor sprayed PCM PIN C11 Tan wire Key On with brake cleaner here As Engine Off sensor tip cools voltage here increases VACUUM 01n Hg STATUS KOEO Key On Engine Off i E eee sa MILEAGE 123686 Troubleshooting Tips Check the manufacturer s specifications for exact voltage range specifications but generally the sensor s voltage should range from 3 V to just under 5 V when stone cold dropping to around 1 to 2 V at operating temperature The good sensor must generate a signal with a certain amplitude at any given temperature Opens in the IAT sensor circuit will appear as upward spikes to V Ref Shorts in the IAT sensor circuit will appear as downward spikes
107. n this mode every noise spike of 40 ns and wider will be displayed INPUT A Control Functions When you are in SCOPE you can control the INPUT A functions as follows SCOPE INPUT INPUT SINGLE 0 EYS A B sHor TRIGGER Yiove A DD DO B f SCOPE INPUT A COUPLING a FOKEYS BACK Pi JEN Press to retum to the a n A CBU Press to invert the INPUT A previous menu signal waveform Press to select DC AC or GROUND coupling DC Coupling allows you to measure and display both the DC and AC components of a signal AC Coupling blocks the DC component and passes the AC component only GND grounds the input of the instrument internally INPUT B Control Functions When you are in SCOPE you can control the INPUT B functions as follows SCOPE INPUT a SINGLE ell A sHoT TRIGGER CD ED CD ED GBD SCOPE INPUT B n e INVERT lt lt EYS u Woe tr CF3 FA CFS Press to invert the INPUT B Press to turn INPUT B on or off signal waveform Press to select DC AC or GROUND coupling When you entered SINGLE DISPLAY INPUT B is turned off by default but you can turn it on by pressing F2 Single Shot Function Normally the scope mode automatically repeats the measurements to acquire waveforms by the recurrent acquisition mode 7 SINGLE SHOT allows you to perform single acquisition to snap events that occur only once REPEAT TEST C3 is used to start a next single acquisition SCOPE INPUT INPUT SIN
108. n to the previous display Power Sources and Charging the Battery The instrument can be powered from any of the following sources e Internal Battery Pack This is a rechargeable Ni MH Battery Pack already installed e Power Adapter The Power Adapter Battery Charger powers the instrument from a standard AC outlet and charges the installed Ni MH Battery Pack The instrument can be used during battery charging Verify that your local line voltage is appropriate before using the Power Adapter to power the instrument e Charging Adapter Optional This adapter charges the instrument s Ni MH Battery Pack from a standard 12 V DC cigarette lighter outlet AA WARNING TO AVOID ELECTRICAL SHOCK USE A BATTERY CHARGER THAT IS AUTHORIZED FOR USE WITH THE AUTOMOTIVE SCOPE USE the following procedure to charge the battery pack and to power the instrument 1 Connect the Power Adapter Battery Charger to line voltage 2 Insert the Power Adapter s low voltage plug into the Power Adapter connector of the instrument You can now use the instrument while the Ni MH batteries are being charged slowly If the instrument is turned off the batteries are charged more quickly During operation when the batteries are low a battery symbol Z appears on the top right of the display When this occurs replace or recharge the internal battery pack immediately 3 The Power Adapter uses a trickle charging method for the batteries so no damage can occur eve
109. nator Output Alternator Field VR Alternator Diode Audio System DC Switch Circuits IGNITION TESTS MENU PIP SPOUT DI Primary DI Secondary DIS Primary DIS Secondary 4 11 Getting Reference Information for the Selected Test Reference information is available at any time by pressing the HELP key Press Fi when finished viewing each area under the HELP menu HELP HELP MENU REFERENCE WAVEFORM THEORY OF OPERATION TROUBLESHOOTING TIPS FUNCTION INFORMATION D C Getting Information About the Function Keys During a Running Test uep When you press this key during a running test you get information about the function keys that can be used for the test For example 4 12 DI Primary Page 1 of 2 Function Info VEHICLE CYLINDER FAST 4 KEYS DATA SINGLE UPDATE TRIG LVU VEHICLE Gives a list of options to define DATA the type of vehicle under test CYLINDER SINGLE displays the ignition ENEAN pattern of one single cylinder PARADE PARADE displays the ignition pattern of all cylinders in firing order DI Primary Page 2 of 2 Function Info VEHICLE CYLINDER FAST KEYS DATA SINGLE UPDATE TRIG LVL FAST Turns all readings off to make the UPDATE measurement faster and more reliable KEYS You can adjust trigger level for a GASH stable display by using the four way arrow keys BACK Figure 7 Information About the Function keys Screen Displays FIRE 11 3kV RPM
110. ncy The time between events or cydes of the electronic signal usually given in cydes per second Hertz Shape The Sue of the electronic signal with its unique curves contours and corners Duty Cycle The on time or relative pulse width of the electronic signal e Pattern The repeated patterns within the signal that make up specific messages like synchronous pulses that tell the PCM that cylinder 1 is at TDC Top Dead Center or a repeated pattem in the serial data stream that tells the scan tool the coolant temperature is 212 F or 100 C etc 3 3 THE GOLDEN RULE OF ELECTRONIC SYSTEM DIAGNOSIS For the vehicle s computer system to function properly it must send and receive signals with the critical characteristics it was designed to communicate with Each of the primary types of electronic signals use the critical characteristics to establish electronic communication They each use different combinations of the critical characteristics to communicate Here s a list of which critical characteristics each of the primary signal types uses to communicate e Direct Current signals use Amplitude only e Alternating Current signals use Amplitude Frequency and Shape Frequency Modulated signals use Amplitude Frequency and Shape Pulse Width Modulated signals use Amplitude Frequency Shape and Duty Cycle Serial Data signals use Amplitude Frequency Shape Duty Cycle and Pattern The list will help to give you a be
111. nd then the closed position again Repeat this process several times e Reference Waveform VEHICLE INFORMATION YEAR 1989 MAKE Chevrolet i MODEL 1500 Series Truck i ENGINE 5 0L FUELSYS Throttle Body Fuel Injection PCM_PIN C13 DkBlu wire STATUS KOEO Key On Engine Off ov Closed Throttle Closed Throttle i RPM 0 Wi jt ENG_TMP Operating Temperature VACUUM 0n Hg 1x Aua f nav et MILEAGE 108706 Troubleshooting Tips Check the manufacturer s specifications for exact voltage range Generally the sensor output should range from just under 1 V at idle to just under 5 V at wide open throttle WOT There should be no breaks spikes to ground or dropouts in the waveform Peak voltage indicates WOT identifies enl t F j a A EE short to ground or an intermittent open in the sensor s Voltage increase throttle plate closing carbon track resistance materials identifies enrichment DC offset indicates voltage at key on throttle closed Voltage decrease Dropouts on the slopes of the waveform indicate a The first 1 8 to 1 3 of the sensor s carbon track usually wears out most because this portion is most used while driving Thus pay particular attention to the waveform as it begins to rise Minimum voltage indicates closed throttle plate Defective TPS Pattern Magnetic Crankshaft Position CKP Sensor e Theory of Operation The magnetic CKP sensors are AC
112. ndary Contents Menu Overview 1 Introduction 1 1 Comparing Scan Tools DSOs and DMMs 1 2 Vehicle Service Manuals s sssscsssscssesssssssensessessssnsssssesssessesancans sesauseesessssensesseeesesaesansenseesesensensesnsensaesanss 1 2 2 Safety Information 3 Automotive Electronic Signals 3 1 Primary Signal Types Found in Modern Vehicles s essere t rterrrnnnttrsentnmtnrtntnmt mrte enee 3 1 3 2 Critical Characteristics of Automotive Electronic Signals 1777n mn 3 2 3 3 The Golden Rule of Electronic System DiaQnOsis sssssssssssentiees cersseesssssnnnnnineeneeeseseensensaney 3 2 3 4 Signal Probing with an Oscilloscope Sl Ste Las ae A hl ag te ny Cella E Nyes 3 2 4 Getting Started 4 1 Product Description een E AEA E E E EE EEE E E E E A E EE 4 1 4 2 QUICK Tour eeereeeee i 2 4 3 Front Panel Controls 4 6 4 4 Measurement Connections sscssesssssssesssnssessssesnssssssnssessesoncenese sauseesessssnsesseenssesesansessessesensessesnesesaesanss 4 7 4 5 Grounding Guidelines 46 Display EEEN E Ee TETAN 4 7 SCOPE Mode 4 8 GMM GRAPHING MULTIMETER Mode 111 i1ttttttrtriir ttt teta enedledenatnbicntnieee 5 Instrument Operation 5 1 Instrument Test Modes ststsssssssssssesssssesssesensenseesessessnsesseeesnesaesance euaesanseesessesensesssensaesaesanseesesssssnsensesnseesaesanss 5 1 5 2 SCOPE Displays AE tian iran nial ar ee ti ee ae ee 5 1 5 3 GMM Displays Nae Sat ee eesti a
113. ning let the engine idle or use the throttle to accelerate or decelerate the engine or drive the vehicle as needed to make the driveability or emissions problem occur 3 Use the Glitch Snare mode to catch dropouts or stabilize waveforms when a sync pulse is created 6 12 e Reference Waveform VEHICLE INFORMATION YEAR 1987 MAKE Chrysler MODEL Fifth Avenue ENGINE 5 2L FUELSYS Feedback Carburetor PCM_PIN 5 1 Org wire 9 1 Blk wire STATUS KOER Key On Running RPM 1400 ENG_TMP Operating Temperature VACUUM 19 In Hg site an RAN ms MILEAGE 140241 The amplitude and frequency increase with engine speed RPM The amplitude frequency and shape should be all consistent for the conditions RPM etc repeatable except for sync pulses and predictable Generally the oscillations may not be perfect mirror images of each other above and below the zero level mark but they should be relatively close on most sensors Troubleshooting Tips Make sure the frequency of the waveform is keeping pace with engine RPM and that the time between pulses only changes when a sync pulse is displayed This time changes only when a missing or extra tooth on the reluctor wheel passes the sensor That is any other changes in time between the pulses can mean trouble Look for abnormalities observed in the waveform to coincide with an engine sputter or driveability problem Before assuring the sen
114. nt to the PCM and the PCM uses this signal to monitor results and accurately time the fuel injector and electronic spark timing output SPOUT signals The PCM sends the SPOUT back to the TFI module which then fires the ignition coil primary circuit The PIP signal is primarily a frequency modulated signal that increases and decreases its frequency with engine RPM but it has also a pulse width modulated component because it is acted upon by the TFI module based on information previously received via the SPOUT signal The SPOUT signal is a pulse width modulated signal because the PCM continually alters the SPOUT signal s pulse width which has the primary ignition dwell and ignition timing advance information encoded in it The frequency of the SPOUT signal also increases and decreases with engine RPM because it simply mimics the frequency of the PIP signal Many GM European Asian vehicles use a similar overall ignition circuit design The rising and falling edges of the SPOUT move in relation to PIP The rising edge controls spark timing and the falling edge controls coil saturation dwell Watching both simultaneously using this instrument will tell you whether the PCM can compute timing based on sensor inputs For example if the MAP sensor fails the rising edge of SPOUT will not move relative to the rising edges of PIP when Manifold Absolute Pressure changes Symptoms Engine stall out misfire slow advance timing hesitations no start
115. ntly a trouble code is generated But to keep warranty costs in line tolerances aren t set to catch all transients even though they can cause some of your worst driveability problems Therefore repair technicians are finding more and more uses for a Digital Storage Oscilloscope DSO and a Digital Multimeter DMM thesedays A DSO can capture a live signature of a circuit and store it for later analysis or comparison against Known good waveforms an invaluable resource for detecting marginal components A GMM Graphing Multimeter gives you advanced multimeter capabilities coupled with the visual power of trend graphing and waveform display This Meter a combination DSO and GMM represents the most powerful and versatile tool available for troubleshooting automotive electronics since we can track down elusive no code driveability problems 1 1 COMPARING SCAN TOOLS DSOs AND DMMs All of these tools have unique capabilities and today s vehicles demand that automotive technicians are able to use all three tools to correctly diagnose various driveability problems DSOs alone cannot replace DMMs or scan tools By the same token DMMs or scan tools cannot replace DSOs For example when anti lock brakes on your car are sometimes erratic you might firstly try a road test to notice that the ABS light does not come on When you get back to the shop you plug in your scan tool and find no trouble codes Because you still have your DMM yo
116. o be connected to the CH A input of the instrument e Reference Waveform DUR Duration of the injection pulse DUR 0 6 ms w eR v f P eae NO ee fA mare te 1V Niy Auto f 15V 5 mr e Analysis of Injection Pattern at Idle Speed The delivery valve opens When the injector opening and a pressure wave pressure is reached to more than proceeds toward the 1 470 psi 100 Bar the needle injector valve overcomes its needle spring ae J J y force and lifts P ji j The injection process ends the delivery valve closes and the s j pressure in the fuel line drops T The injection pumps plunger This quick drop causes the nozzle to close instantly preventing the nozzle from opening again and preventing backflow of combustion gases moves in the supply direction and thus generating a high pressure in the pressure gallery 6 69 Diesel Advance Diesel pump testers are used to calibrate pumps exactly to the engine s requirements The testers monitor the signals from the reference on the engine s flywheel The start of the delivery is monitored and timing adjustments can be made at different speeds We can reveal problems in the timing of the start of fuel delivery compared to the TDC signal of the flywheel sensor through this advance measurement which cannot be an absolute and accurate diesel pump adjustment test Test Procedure 1 Clamp the piezo pickup and its gro
117. o the temperature to the PCM FT sensors usually sense the engine s fuel temperature in the fuel rail When this instrument is connected to the signal from a FT sensor what is being read is the voltage drop across the sensor s NTC resistor Typically FT sensor s resistance ranges from about 100 000 ohms at 40 F 40 C to about 50 ohms at 266 F 130 C e Symptoms OBD II DTC s P0180 P0184 P0185 P0189 Hard start poor fuel economy driveability problems Test Procedure 1 Backprobe the terminals on the FT sensor with the CH A lead and its ground lead 2 Start the engine and hold the throttle at 2500 RPM until the trace goes across the screen 3 Set the time base to 50 sec div to see the sensor s entire operating range from stone cold to operating temperature 4 Press the HOLD key to freeze the waveform on the display for closer inspection 5 To measure resistance disconnect the sensor before changing to the GMM mode and then connect the Ground and CH A leads to the terminals on the sensor Reference Waveform VEHICLE INFORMATION MAX 3 13 V F Engine warmed YEAR i 1988 up for 8 minutes MAKE Nissan Datsun here MODEL 300 ZX non turbo i a en SE we ENGINE 3 0L 2v Engine stone i FUELSYS Multiport Fuel Injection cold here PCM_PIN 15 Yel wire STATUS KOER Key On Running m m RPM 2000 i j ENG_TMP Warming Up VACUUM 21 In Hg a eee SAs MILEAGE 57782 e Troubleshootin
118. of oxygen in the exhaust stream respectively before and after the catalytic converter The leading sensor signal is used as feedback for controlling the fuel mixture The trailing sensor signal is used by PCM to test efficiency of the catalytic converter The signal amplitude from the trailing sensor will increase when the efficiency of the catalytic converter declines over years A good O2 sensor located downstream from the catalyst should see much less fluctuations than its upstream counterpart during steady state operation This is due to the properly operating catalyst s ability to consume oxygen when it is converting HC and CO thus dampening the fluctuations in the downstream sensor s signal That is the difference in voltage amplitude from the sensors is a measure for the ability of the catalyst to store oxygen for the conversion of harmful exhaust constituents 6 4 e Symptoms OBD II DTC s P0420 P0424 P0430 P0434 Emissions test failure poor fuel economy e Test Procedure 1 Connect one shielded test lead to the CH A and the other test lead to the CH B Connect the ground leads of both test leads to the engine GND s and one lead probe to the sensor 1 upstream sensor output or HI and the other lead probe to the sensor 2 downstream sensor output or HI 2 Run the engine until the O2 sensors are warmed to at least 600 F 315 C in closed loop operation 3 Run the engine at idle while increasing engine speed 4 Use
119. of the vane air flow door As the engine is accelerated and more air passes through the vane air flow sensor the vane air door is pushed open by the incoming air The angle of the vane air flow door is proportional to the volume of air passing by it A vane type MAF sensor consists of a contact connected to the vane door which slides over a section of resistance material that is places around the pivot axis for the movable contact The voltage at any point in the resistance material as sensed through the movable contact is proportional to the angle of the vane air door Overswing of the door caused by snap accelerations provides information to the PCM for acceleration enrichment Many Toyotas are equipped with vane type MAF sensors operating opposite the above their voltage is high when airflow is low Symptoms OBD II DTC s P0100 P0104 Hesitation stall low power idle problems excessive fuel consumption emissions failure e Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 Shut off all accessories start the engine and let it idle in park or neutral After the idle has stabilized check the idle voltage 3 Rev the engine from idle to Wide Open Throttle WOT with a moderate input speed this should only take about 2 seconds don t overrev the engine 4 Let engine speed drop back down to idle for about two seconds 5 Rev the engine again to WOT ver
120. om one of the built in COMPONENT TESTS Each test places the instrument in a configuration best suited to display signals for the chosen device or circuit Press a Four Way arrow key to position the HIGHLIGHT BAR over the COMPONENT TESTS menu choice and press CE5 to select MAIN MENU COMPONENT TESTS SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP D CED Figure 2 Main Menu From the resulting COMPONENT TESTS menu select IGNITION from the test group Then press F5 to select COMPONENT TESTS MENU SENSORS ACTUATORS ELECTRICAL GD E Figure 2 Selecting IGNITION Menu Next press the Four Way arrow keys to highlight PIP SPOUT Press F5 to select Now the instrument is ready to test the input signal s HOLD gt SCOPE A AAA AAA EUU UTLU RAA MTARNTRGRTATITD WUUUUUUUVUI A10V Bi0V Awo f 60V 10ms IGNITION _PIP SPOUT CFL CFS CED Figure 3 Example of Result Display Press F3 to remove the Reference Waveform s Press CF5 to enter the scope into the test mode and continue to display the Reference Waveform s for comparison to a live waveform s For this demonstration view the following reference information specific to the test selected Reference information is available at any time by pressing the HELP key Press F1_ when finished viewing each area under the HELP menu Test Procedure Tells how to hook up the scope and what accessories to use Describes
121. ontrol current is varied according to the battery s need for charge and ambient temperature If the battery is discharged the regulator may cycle the field current on 90 of the time to increase the alternator output If the electrical load is low the regulator may cycle the field current off 90 of the time to decrease the alternator output That is the signal is usually pulse width modulated If the field control circuit is malfunctioning the charging system can overcharge or undercharge either creating problems Symptoms Undercharging overcharging or no charging output Test Procedure 1 Connect the CH A lead to the field control circuit and its ground lead to the chassis GND 2 Start the engine and run at 2500 RPM Operate the heater fan on high with the headlight on high beam or use battery load tester to vary the amount of load on the vehicle s electrical system 3 Make sure that the voltage regulator is properly controlling the duty cycle of the alternator field drive signal as the load changes e Reference Waveform VEHICLE INFORMATIONS FREQ 390 Hz YEAR 1986 MAKE Oldsmobile MODEL Toronado ENGINE 3 8L w perapan pn pene FUELSYS Multiport Fuel Injection 3 i PCM_PIN 3D11 at BCM Grey wire at alternator pin F DEISE iE RPM 2500 ov eman ENG_TMP Operating Temperature MILEAGE 123638 highbeam MILEAGE 123686 SV Auto f 4nv gt ms The charging system s voltage regulator should va
122. or decelerate the engine or drive the vehicle as needed to make the driveability or emissions problem occur 3 Use the Glitch Snare mode to catch dropouts or stabilize waveforms when a sync pulse is created e Reference Waveform VEHICLE INFORMATION hese i Frequency Modulated signal YEAR 1989 MIN 133 mV _ Frequency increases with MAKE Mitsubishi peri ne ae MODEL Montero ev i ENGINE 3 0L avibt ef f FUELSYS Multiport Fuel Injection StGGGee PCM_PIN 22 Blk wire at PCM wE i L STATUS KOER Key On Running ol ae ie RPM Idle ENG_TMP Operating Temperature VACUUM 20 In Hg 2V Ato f 18V 500 us MILEAGE 184066 The amplitude frequency and shape should be all consistent in the waveform from pulse to pulse The amplitude should be sufficient the time between pulses repeatable except for sync pulses and the shapes repeatable and predictable Consistency is the key Troubleshooting Tips The duty cycle of the waveform changes only when a sync pulse is displayed Any other changes in duty cycle can mean troubles The top and bottom corners of the waveform should be sharp However the left upper corner may appear rounded on some of the higher frequency high data rate optical distributors This is normal Optical CKP sensors are very susceptible to malfunction from dirt or oil interfering with the light transmission through the rotating disk When dirt or oil enters into the sensitive a
123. oting Tips If the turn off spikes are not present the solenoid coil may be shorted If the drive signal never appears under the high boost conditions the driver within the PCM may have failed If the turn off spikes are runted shortened the vacuum solenoid valve may be shorted 6 46 Diesel Glow Plug e Theory of Operation Starting cold diesel engines are not easy because Blowby past the piston rings and thermal losses reduce the amount of compression possible Cold starting can be improved by a sheathed element glow plug in the precombustion chamber in case of Direct injection DI engines in the main combustian chamber When current flows through the heating coil of the glow plug a portion of the fuel around the glow plug s hot tip is vaporized to assist in igniting the air fuel mixture Newer glow plug systems which continue to operate after engine startup for up to 3 minutes improve initial engine performance reduce smokes emissions and combustian noises Usually a glow plug control unit supplies power to the glow plug during appropriate conditions Some newer glow plugs are designed with a heater element that changes resistance with temperature The glow plug s resistance increases as the heating element gets hotter by the combustian temperature s increment after startup Usually glow plug systems are power feed controlled so the waveform of the current going through its heating element appears as a straight line at 0
124. ower than the normal ones shown above A shorted diode splits the pulses into pairs Troubleshooting Tips If the waveform has very noticeable dropouts with two or three times the peak to peak amplitude of a normal ripple the diodes are defective Dropouts from bad diodes usually have a peak to peak voltages of around 1 5 V to 2 0 V If the humps in the waveform are grouped into pairs the alternator has one or more bad diodes Audio System Speaker e Theory of Operation Automotive speakers are electromechanical devices that convert electrical signal from a vehicle s radio or monitoring system into mechanical vibrations The mechanical vibrations produced by automotive speakers are in the audible frequency range from 16 to 20 000 Hz Audio signals to the speaker usually range between 0 5 and 10 V Peak to Peak DC resistance of the speaker voice coils is normally less then 10 ohms e Symptoms A blown speaker with an open circuit e Test Procedure 1 Connect the CH A lead to the positive speaker circuit and its ground lead to the negative speaker circuit 2 Turn on the radio at normal listening level and make sure that the speaker drive signal is present 3 To measure the resistance of the speaker voice coils set the instrument to the GMM mode Measure the resistance with the drive signal disconnected 6 55 Reference Waveform VEHICLE INFORMATIONS YEAR 1989 er MAKE Buick UL ae MODEL Le Sab
125. parking brake does not hold the drive wheels e Be sure there is adequate clearance between any moving components when testing Moving components and belts can CATCH loose clothing parts of your body or the instrument and cause serious damage or personal injury e Always wear approved safety eye protection when testing or repairing vehicles Objects can be propelled by whirling engine components can cause serious injury e When handling any signals higher than 150 V peak don t electrically activate BOTH CH A and or CH B terminal s AND USB terminal together at a time If they are electrically activated simultaneously a death or a serious personal injury could be resulted in 2 1 Avoid Fires e Do not position head directly over carburetor or throttle body Do not pour gasoline down carburetor or throttle body when cranking or running engine Engine backfire can occur when air cleaner is out of normal position Do not use fuel injector cleaning solvents or carburetor sprays when performing diagnostic testing e The instrument has internal arcing or sparking parts Do not expose the instrument to flammable vapors e Do not smoke strike a match place metal tools on battery or cause a spark in the vicinity of the battery Battery gases can ignite e Keep a fire extinguisher rated for gasoline chemical and electrical fires in work area Fires can lead to serious injury or death BS WARNING Avoid Electrical Shock e Make sure tha
126. poor fuel economy low power high emissions Test Procedure 1 Connect the ground leads of both channel test leads to the chassis GND s Connect the CH A to the PIP signal and the CH B to the SPOUT signal Use a wiring diagram for the vehicle being serviced to get the PCM pin number or color of the wire for each circuit 2 Crank or start the engine 3 With the Key On Engine Running KOER let the engine idle or use the throttle to accelerate and decelerate the engine or drive the vehicle as needed to make the driveability problem occur 4 Look closely to see that the frequency of both signals is keeping pace with engine RPM and that the pulse width on the pulse width modulated notches of the signal changes when timing changes are required 5 Look for abnormalities observed in the waveforms to coincide with an engine sputter or driveability problem 6 58 e Reference Waveform VEHICLE INFORMATIONS _ Ford EEC IV PIP and SPOUT YEAR 1993 signals 0gg8d at 3000 RPM MAKE Ford i MODEL F150 4WD Pickup wA fi ri ii r ENGINE 5 0L owe LJ Uf Ld Lead LE ld Made ited ad FUELSYS Multiport Fuel Injection miala ir A PCM_PIN CH A 56 GryOrg wire aaa nE aT i avi CH B 36 Pnk wire Cd aa r a To ee en STATUS KOER Key On Running i RPM 3000 ENG_TMP Operating Temperature A 10V BW iV uto f nv Nma VACUUM 21 In Hg MILEAGE 66748 The edges must be sharp Anything that affects ignition timing should change the posit
127. r source voltage Injector On Time Symptoms Hesitation on throttle tip in rough idle intermittent stall at idle poor fuel mileage emissions test failure low power on acceleration e Test Procedure 1 Connect the CH A lead to the injector control signal from the PCM and its ground lead to the injector GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System enters closed loop Verify this by reviewing the O2 sensor signal if necessary 3 Shut off A C and all other accessories Put vehicle in park or neutral Rev the engine slightly and watch for the corresponding injector on time increase on acceleration 1 Induce propane into the intake and drive the mixture rich If the system is working properly the injector on time will decrease 2 Create a vacuum leak and drive the mixture lean The injector on time will increase 3 Raise the engine to 2500 RPM and hold it steady The injector on time will modulate from slightly larger to slightly smaller as the system control the mixture Generally the injector on time only has to change from 0 25 ms to 0 5 ms to drive the system through its normal full rich to full lean range IMPORTANT If the injector on time is not changing either the system may be operating in an open loop idle mode or the O2 sensor may be bad 4 Use the Glitch Snare mode to check for sudden changes
128. raise combustion temperatures above 2500 F The initial formation of NOx is limited by EGR flow and then the catalytic converter acts to chemically reduce the amounts of produced NOx entering the atmosphere 6 40 How much and when EGR flow occurs is very important to emissions and driveability To precisely control EGR flow the PCM sends Pulse Width Modulated signals to a vacuum solenoid valve to control vacuum flow to the EGR valve When applying vacuum the EGR valve opens allowing EGR flow When blocking vacuum EGR flow stops Most engine control systems do not enable EGR operation during cranking engine wam up deceleration and idling EGR is precisely controlled during acceleration modes to optimize engine torque e Symptoms Hesitation loose power stall emissions with excessive NOx engine detonation pinging e Test Procedure 1 Connect the CH A lead to the EGR control signal from the PCM and its ground lead to GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System enters closed loop Verify this this by viewing the O2 sensor signal 3 Shut off A C and all other accessories Drive the vehicle under normal driving modes start from dead stop light acceleration heavy acceleration cruise and deceleration 4 Make sure that the amplitude frequency shape and pulse width are all correct repeatable and present during EGR flow conditions
129. re At A rH ti mT ENGINE 3 8L IAN My LA H ia NN Aa ARAN FUELSYS Multiport Fuel Injection y i Mi iil PCM_PIN CH A to speaker ani music starts new it aL CONTIG speaker g Se sansi STATUS KOEO Key On Engine Off RPM 0 ENG_TMP Ambient Temperature ACAR f Aua nav ee VACUUM Oln Hg MILEAGE 93640 A few notes from Willie Nelson s On The Road Again Automotive speaker drive signals nomally range between 0 5 V and 10 V Peak to Peak Resistance of the speaker voice coils is normally less than 10 ohms Troubleshooting Tips If the speaker is blown suspect an open circuit DC Switch Circuits e Theory of Operation This test procedure can be applied to a lot of different automotive circuits that use B as their power source such as power supply circuits to the PCM and other control modules temperature switches throttle switches vacuum switches light switches brake switches cruise control switches etc This test can be used to test the integrity of the battery power supply to the switches that rely on the battery power to operate Symptoms No start lose of power no working of switches Test Procedure 1 Connect the CH A lead to the power supply circuit of the switch to be tested and its ground lead to the switch GND circuit 2 Make sure power is switched on in the circuit so that the switch is operational 6 56 3 Exercise the switch while paying attention to
130. re sensor supplied with 5 V V Ref power a ground circuit and the digital signal output pulses based on the amount of vacuum it senses Symptoms OBD II DTC s P0105 P0109 Low power stall hesitation excessive fuel consumption emissions failure e Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With the Key On Engine Off KOEO apply different amounts of vacuum to the sensor using a handheld vacuum pump 6 24 3 Make sure that the amplitude frequency and shape are all present repeatable and consistent Amplitude should be close to 5 V Frequency should vary with vacuum Shape should stay constant square wave 4 Make sure the sensor produces the correct frequency for a given amount of vacuum according to the specification chart for the vehicle you are working on 5 Use the Glitch Snare mode to detect dropouts or unstable output frequency e Reference Waveform VEHICLE INFORMATIONS FREQ 159 Hz YEAR 1993 MAX 5 06 V i 5 MIN 133 mV y MAKE Ford key On Engine Of KOEO MODEL F150 4WD Pickup ENGINE 5 0L n T AN Anen eNi FUELSYS Multiport Fuel Injection mi 1 PCM_PIN 45 LtGrn Blk wire S STATUS KOEO Key On Engine Off ow PN ee i Lees RPM 0 ENG_TMP Operating Temperature VACUUM 0 lIn Hg on en SRY ims MILEAGE 66748 Frequency decreases as vacuum increases Look for pulses that are a fu
131. reas of the sensors no starts stalls or misfires can occur Magnetic Camshaft Position CMP Sensor e Theory of Operation The magnetic CMP sensors are AC signal generating analog sensors The generally consist of a wire wrapped soft bar magnet with two connections These two winding or coil connections are the sensor s output terminals When a ring gear a reluctor wheel rotates past this sensor it induces a voltage in the winding A uniform tooth pattern on the reluctor wheel produces a sinusoidal series of pulses having a consistent shape The amplitude is proportional to the rotating speed of the reluctor wheel that is the crankshaft or camshaft The frequency is based on the rotational speed of the reluctor The air gap between the sensor s magnetic tip and the reluctor wheel greatly affects the sensor s signal amplitude They are used to determine where TDC Top Dead Center position is located by creating a synchronous pulse which is generated by either omitting teeth on the reluctor wheel or moving them closer together The PCM or ignition module uses the CMP sensors to trigger ignition or fuel injector events The magnetic CMP and CKP sensors are susceptible to Electromagnetic Interference EMI or RF from high voltage spark plug wires car phones or other electronic devices on the vehicle This can cause a driveability problem or set a Diagnostic Trouble Code DTC Symptoms OBD II DTC s P0340 P0349 P0365 P
132. rmined voltage range for a given condition 4 In most cases the amplitude of the waveform should stay at the battery voltage when the circuit is on and go to 0 V when the circuit is off e Reference Waveform VEHICLE INFORMATIONS YEAR 1986 MAKE Oldsmobile MODEL Toronado ENGINE 3 8L FUELSYS Multiport Fuel Injection se PCM_PIN C16 Org and D1 BIkWht wires ov PCM ower and ground STATUS KOER Key On Running wiggle or shake wiring harness or RPM Idle transient spikes are normal H with engine running j wires to suspect component while ENG_TMP Operating Temperature looking for drop outs in the waveform VACUUM 20 In Hg ai Pere ON t MILEAGE 123686 The voltage should stay in a predetermined voltage range for a given condition during nomal operation Transient spikes above average voltage level are normal with engine running Troubleshooting Tips If the amplitude is changing when it is not supposed to for example when the switch in the circuit is not being operated there may be a failure in the circuit If the waveform has some spikes to ground there may be an open circuit in the power side or there may be a voltage short to ground If the waveform has some upward spikes there may be an open circuit in the ground side Voltage Reference V Ref Circuit Theory of Operation The PCM provides a stable regulated voltage normally 5 V DC 8 V or 9 V DC on some older vehicles to
133. rotor spark gap For accurate measurements use the coil secondary signal before the distributor NOTE If you want to test SECONDARY IGNITION SINGLE press to highlight SINGLE and SECONDARY IGNITION PARADE press F4 to highlight PARADE 4 With the Key On Engine Running KOER use the throttle to accelerate and decelerate the engine or drive the vehicle as needed to make the driveability problem or misfire occur 5 Make sure that the amplitude frequency shape and pulse width are all consistent from cylinder to cylinder Look for abnormalities in the section of the waveform that corresponds to specific components e Reference Waveform VEHICLE INFORMATIONS TA YEAR 1984 DUR 2 39 ms MAKE Mercedes Benz MODEL 380 SE ENGINE 3 8L FUELSYS CIS Fuel Injection PCM_PIN CH A to the Coil wire STATUS KOER Key On Running RPM Idle ENG_TMP Operating Temperature VACUUM 19 5 In Hg MILEAGE 18575 Look closely to see that the pulse width dwell changes when engine load and RPM changes 6 63 Troubleshooting Tips Look for the drop in the waveform where the ignition coil begins charging to stay relatively consistent which indicates consistent dwell and timing accuracy of individual cylinder Look for a relatively consistent height on the arc over voltage or firing line A line that is too high indicates high resistance in the ignition secondary due to an open or bad spark plug wire or a large sp
134. rrent display This makes it possible to examine occasional waveform anomalies and to stop the GMM mode at the end of a manual sweep test The instrument provides four memory locations to which you can save the current screen along with its setup in the Scope GMM Component Test and Glitch Snare modes Press HOLD to freeze the current display and show the Function Key Menu to save recall or to clear the memory HOLD indicator appears in the top right of the display when the HOLD key is pressed In each Scope GMM Component Test or Glitch Snare mode the operation sequency of the SAVE RECALL and CLEAR function is as follows SAVE RECALL RECALL BACK SAVE MEMORY GLIT SN CLEAR Previous State MEMORY SAVE Empty MEMORY ERASE Scope SEARCH SEARCH BACK tee BACK ED ED ED CF4 C5 Save memory MEMORY RECALL Scope SEARCH WFM BACK Sgach Waveform On Off 5 17 5 7 GLITCH SNARE OPERATION Glitch Snare is a powerful combination of capabilities which enables you to reliable capture and display Actual Signal Waveforms associated with elusive and unusual signals Glitch Snare combines real time measurements with specially designed scope trigger facilites monitoring measurement results on an event by event basis and triggering on any result which deviates above or below the norm by more than a present limit The input signal is captured at the moment when a trigger event occurs Im
135. ry the on time of the altemator s field control drive signal depending on the electrical system requirements The regulator should pulse the field drive signal with the overall duty cycle average meeting the electrical system demands When electrical load is put on the battery the field control circuit should go high to compensate for it Frequency may increase during conditions of increased charging demand 6 53 Troubleshooting Tips If the voltage is high there is no command to turn the alternator on or the regulator does not have the ability to decrease the voltage If the voltage is low the alternator will be on all the time and cause an overcharging state If the voltage can not be pulled to ground sufficiently there may be bad regulator within the PCM Alternator Diode e Theory of Operation An alternator generates current and voltage by the principles of electromagnetic induction Accessories connected to the vehicle s charging system require a steady supply of direct current DC at a relatively steady voltage level A set of diodes part of the altemator s rectifier bridge modifies the AC voltage produced in the alternator to the DC voltage When analyzing a vehicle s charging system both AC and DC level should be analyzed because the AC level called ripple voltage is a clear indication of diode condition Too high a level of AC voltage can indicate a defective diode and discharge the battery Usuall
136. sensors and components controlled by it for operation The V Ref circuit should stay at their specified voltage during normal operation The voltage level should not vary more than 200 mV under normal operation Symptoms Low power sensor output values out of range e Test Procedure 1 Connect the CH A lead to the V Ref signal from the PCM and its ground lead to the sensor or chassis GND 6 49 2 Make sure power is switched on to the PCM and monitor the voltage level of the V Ref signal from the PCM Compare it with the manufacturer s recommended limits 3 If the voltage level is unstable or the waveform shows spikes to ground check the wiring harness for shorts or intermittent connections Reference Waveform VEHICLE INFORMATIONS MAX 5 33 V Sensor Reference Voltage sent out by PCM Supplies YEAR 1986 voltage to various sensors MAKE Oldsmobile Waveform s amplitude should MODEL Toronado not vary more than 200 mV i ENGINE 3 8L 10v ig fle a oe FUELSYS Multiport Fuel Injection 5V i PCM_PIN C14 Gry wire at TPS we wiggle the sensor harness wirin STATUS KOER Key On Running while watching the Waren RPM Idle amplitude to check for bad 1 ENG_TMP Operating Temperature connections or chafed wires VACUUM 18 In Hg ESY Auno f ARV 50 ms MILEAGE 123686 The voltage should stay in a predetermined voltage range fora given condition Normal V Ref voltage ranges are from 4 50 V to 5 50 V Troubleshoo
137. should range about 1 25 Vat idle to just under 5 V at WOT and close to 0 V on full deceleration High vacuum around 24 In Hg on full decel produces low voltage close to 0 V and low vacuum around 3 In Hg at full load produces high voltage close to 5 V IMPORTANT There are a few MAP sensors designed to do the opposite high vacuum high voltage Some Chrysler MAP sensors just stay at a fixed voltage when they fail regardless of changes in vacuum level Generally 4 cylinder engines make nosier waveforms because their vacuum fluctuates more between intake strokes e Troubleshooting Tips A high voltage level indicates Z high intake manifold pressure HIGH ENGINE LOAD low vacuum LOW ENGINE LOAD As the throttle plate opens manifold pressure rises manifold vacuum lowers A low voltage level indicates low intake manifold pressure high vacuum Digital Manifold Absolute Pressure MAP Sensor e Theory of Operation Ford s digital MAP sensor is found on many Ford and Lincoln Mercury vehicles from the early 1980 s to well into the 1990 s This sensor produces a frequency modulated square wave whose frequency varies with the amount of intake vacuum sensed It generates about 160 Hz with no vacuum applied and it generates about 105 Hz when it is sensing around 19 In Hg at idle Check the manufacturer s specs for the year make and model for exact vacuum versus frequency reference numbers This is a three wi
138. sion Peak and Hold A method for regulating the current flow through electronic fuel injectors Supplies Single Shot ane measured Dyan oscilo scope that only Occ mis oroe also Called a ansien higher current necessary to energize the injector then drops to a lower level just j enough to keep the injector energized Spark Advance The relationship between the ignition timing and top dead center DTC Pixel The smallest graphic detail possible for the liquid crystal display LCD Spike A high voltage pulse during a short period of time sharp pulse Powertrain The elements of a vehicle by which motive power is generated and transmitted to the Throttle A valve for regulating the supply of a fluid usually air or a fuel air mixture to an engine oriyen axles Time Base The time defined per horizontal division on the display ESE Re eg TePe Sre rere a pelea vee Trace The displayed waveform that shows the variations of the input signal as a function of Pressure Differential The pressure difference between two regions such as between the intake manifold and time the atmosptieric pressures Trigger Determines the beginning point of a waveform PTC A resistor that has a Positive Temperature Coefficient resistance increases as Trigger Level The voltage level that a waveform must reach to start display temperature increases Pulse A voltage signal that increases or decreases from a constant value then returns to the Trigger Slope Te voltage Cecio ma
139. sor before changing to the GMM mode and then connect the Ground and CH A leads to the terminals on the sensor e Reference Waveform VEHICLE INFORMATION ECT Test from stone YEAR 1986 Pee cold to operating temp MAKE Oldsmobile f Thermostat opens MODEL Toronado 7 here ENGINE 3 8L Rn EN ANTA FUELSYS Multiport Fuel Injection z PCM_PIN C10 Yel wire STATUS KOER Key On Running i Engine at PCM resistor operating RPM 1500 ie in temp here ENG_TMP Warming Up ere a VACUUM 18 In Hg E EN S MILEAGE 123686 Troubleshooting Tips Check the manufacturer s specifications for exact voltage range specifications but generally the sensor s voltage should range from 3 V to just under 5 V when stone cold dropping to around 1 V at operating temperature The good sensor must generate a signal with a certain amplitude at any given temperature Opens in the ECT sensor circuit will appear as upward spikes to V Ref Shorts to ground in the ECT sensor circuit will appear as downward spikes to ground level Fuel Temp Sensor Theory of Operation Most Fuel Temperature FT sensors are Negative Temperature Coefficient NTC type thermistors They are primarily two wire analog sensors whose resistance decreases when their temperature increases Some sensors use their own case as a ground so they have only one wire the signal wire They are supplied with a 5 V V Ref power signal and return a voltage signal proportional t
140. sor s failure when waveform abnormalities are observed make sure that a chafed wire or bad wiring harness connector is not the cause the circuit isn t grounded and the proper parts are spinning Hall Effect CranKshaft Position CKP Sensor e Theory of Operation These CKP sensors are classified as CKP Sensors Low Resolution in industry The Hall CKP sensors are low resolution digital sensors which generate the CKP signal that is a low frequency hundreds of Hz square wave switching between zero and V Ref from a Hall sensor The Hall CKP sensor or switch consists of an almost completely closed magnetic circuit containing a permanent magnet and pole pieces A soft magnetic vane rotor travels through the remaining air gap between the magnet and the pole piece The opening and closing of the vane rotor s windows interrupt the magnetic field causing the Hall sensor to turn on and off like a switch so some vehicle manufacturers call this sensor a Hall switch These sensors operate at different voltage levels depending on the vehicle manufacturers and deliver a series of pulses as the shaft rotates They are used to switch the ignition and or fuel injection triggering circuits on and off The PCM uses the Hall CKP sensors to detect misfire Symptoms OBD II DTC s P0340 P0349 P0365 P0369 P0390 P0394 Long cranking poor fuel economy emissions problem Test Procedure 1 Connect the CH A lead to the sensor output
141. ssions with excessive NOx and engine detonation pinging IAC Idle Air Control Motor e Theory of Operation Idle air control valves keep the engine idling as low as possible without stalling and as smoothly as possible when accessories such as air conditioning compressors alternators and power steering load the engine Some IAC valves are solenoids most Fords some are rotating motors European Bosch and some are gear reduction DC stepper motors most GM Chrysler In all cases however the PCM varies the amplitude or pulse width of the signal to control its operation and ultimately idle speed Rotating IAC motors receive a continuous pulse train The duty cycle of the signal controls the speed of the motor and in turn the amount of air bypassing the throttle plate Symptoms Erratic high or low idle stalling high activity but no change in idle e Test Procedure 1 Connect the CH A lead to the IAC control signal from the PCM and its ground lead to GND 2 Run the engine at idle while turning accessories A C blowers wipers etc on and off If the vehicle has an automatic transmission put it in and out of drive and park This will change the load on the engine and cause the PCM to change the output command signal to the IAC motor 3 Make sure that idle speed responds to the changes in duty cycle 4 Use the Glitch Snare mode to check for signal dropouts Reference Waveform VEHICLE INFORMATIONS YEAR _ 1989
142. st of choices for selecting a test a function or a setting Frequenc The number of times a waveform repeats per second measure in Hz 1 Hz equals one 5 cycle per second F 5 Malfunction Indicator A required on board indicator to alert the driver of an emission related malfunction Lamp MIL i iti i fuel f 7 PENEI F oai r PA Aa eE Halle szmat represent nuding Pe SURITICNNO IA from Noise Extraneous electrical signal that can interfere with other electrical signals The noise can i i disturb the function of the signal when it exceeds a certain electrical level A resistor that has a Negative Temperature Coefficient resistance decreases as Scan Tool A device that interfaces with and communicates information on a data link temperature mereases Sample A reading taken from an electrical signal A waveform is created from a successive number of samples On time The part of an electrical signal during which an electrical device is energized Saturated Driver Fuel injection circuit that maintains the same voltage level throughout its on time a g O OBD II Secondary Pickup An accessory that can be clamped on the high voltage coil wire used to measure OBD II S ma secondary ignition patterns 7 3 P Shielded Test Lead A test lead that is surrounded by a conductive screen to protect the measurement signal Peak V lis The highest or lowest value of a waveform Shift Solenoid A device that controls shifting in an automatic transmis
143. t An open circuit may be caused by overheat from a faulty controller vibration or fatigue related malfunctions 6 4 ELECTRICAL TESTS a rA ELECTRICAL TESTS MENU Not Power Circuit COMPONENT TESTS V Ref Circuit Ground Circuit ELECTRICAL Alternator Output Alternator Field VR Alternator Diode Audio System DC Switch Circuits Power Supply Circuit e Theory of Operation This test procedure tests the integrity of the battery power supply to vehicle as well as to subsystems or switches that rely on battery power to operate This test procedure can be used to assure components and devices are getting the quality and quantity of power supply necessary for proper operation This procedure can be applied to a lot of different automotive circuits that use battery voltage as their power source such as power supply circuits to PCM and other control modules temperature switches throttle switches vacuum switches light switches brake switches cruise control switches etc Symptoms No start loss of power Test Procedure 1 Connect the CH A lead to the power supply circuit of the device to be tested and its ground lead to the device s GND 2 Make sure power is switched on in the circuit so that the sensor device or circuit is operational and current is flowing through the circuit 6 48 3 Exercise the sensor device or circuit while watching for the amplitude of the signal The amplitude should stay in a predete
144. t the vehicle to be tested is at a safe potential before making any measurement connections Connect the COM input of the instrument to vehicle ground before clamping the standard SECONDARY PICKUP supplied on the ignition wires This ground connection is required IN ADDITION TO the normal measurement ground connections Do not touch ignition coils coil terminals and spark plugs while operating They emit high voltages e Do not puncture an ignition wire to connect the instrument unless specifically instructed by vehicle manufacturer Be sure the ignition is in the OFF position headlights and other accessories are off and doors are closed before disconnecting the battery cables This also prevents damage to on board computer systems IF the ground of the instrument is connected to a voltage higher than 42 V peak 30 V rms e Use only the standard test leads set supplied with the instrument Do not use conventional exposed metal BNC or BANANA PLUG connectors e Use only one ground connection to the instrument GROUND LEAD of the CH A s shielded test lead e Remove all probes and test leads that are not in use Connect the power adapter to the AC outlet before connecting it to the instrument Follow the general safety guidelines below Avoid working alone e Inspect the test leads for damaged insulation or exposed metal Check test lead continuity Replace damaged leads before use Do not use the instrument if it looks
145. th KOER Key On Engine Running let the engine idle or use the throttle to accelerate or decelerate the engine or drive the vehicle as needed to make the driveability or emissions problem occur 3 Use the Glitch Snare mode to catch dropouts or stabilize waveforms when a sync pulse is created e Reference Waveform VEHICLE INFORMATION FREQ 22 3 Hz MAX 7 33 V Fixed Pulse Width signal l YEAR 1986 i MIN 333 mV Frequency increases with MAKE Oldsmobile ansk ces MODEL Toronado rotation in between pulses ENGINE 3 8L we i FUELSYS Multiport Fuel Injection Bhg ee ee ae PCM_PIN K BrnWht wire at ignition module STATUS KOER Key On Running ov 1 RPM 2500 ENG_TMP Operating Temperature VACUUM 20 In Hg ia A AN Ima MILEAGE 123686 The amplitude frequency and shape should be all consistent in the waveform from pulse to pulse The amplitude should be sufficient usually equal to sensor supply voltage the time between pulses repeatable except for sync pulses and the shape repeatable and predictable Consistency is the key Troubleshooting Tips The duty cycle of the waveform changes only when a sync pulse is displayed Any other changes in duty cycle can mean troubles The top and bottom corners of the waveform should be sharp and voltage transitions of the edge should be straight and vertical Make sure the waveform isn t riding too high off the ground level This could
146. ting Tips If the voltage level is unstable or the waveform shows spikes to ground check the wiring harness for shorts or bad connections Waveform s amplitude should not vary more than 200 mV under normal operation Ground Circuit e Theory of Operation A ground circuit controls the feedback on any controlled circuit by grounding that circuit to a common conductor ground This test procedure tests the integrity of ground circuits by performing a voltage drop test across the suspected resistance in a ground circuit or the suspect junction This test procedure can be used to assure components and devices are getting the quality of ground supply necessary for proper operation This procedure can be applied to a lot of different automotive circuits that are grounded to the vehicle s electrical systems either through the engine block chassis or through a wire connected to the negative side of the battery Symptoms Poor performance inaccurate sensor outputs 6 50 e Test Procedure 1 Connect the CH A lead to the GND pin of the grounded device or the one side of the suspect junction and its ground lead to the chassis GND or the other side of the suspect junction 2 Make sure power is switched on in the circuit so that the sensor device or circuit is operational and current is flowing through the circuit 3 The average voltage drop across the junction should be less than 100 mV to 300 mV e Reference Waveform VEHICLE I
147. tion in each individual cylinder The waveform is primarily used to 1 analyze individual cylinder s dwell coil charging time 2 analyze the relationship between ignition coil and secondary circuit performance from the firing line or ignition voltage line 3 locate incorrect air fuel ratio in individual cylinder from the burn line and 6 59 4 locate fouled or damaged spark plugs that cause a cylinder misfire from the burn line It s sometimes advantageous to test the ignition primary when the ignition secondary is not easily accessible Symptoms No or hard starts stalls misfires hesitation poor fuel economy e Test Procedure 1 Connect the CH A lead to the ignition coil primary signal driven side and its ground lead to the chassis GND 2 With the Key On Engine Running KOER use the throttle to accelerate and decelerate the engine or drive the vehicle as needed to make the driveability problem or misfire occur 3 For cranking test set the Trigger mode to Normal 4 Make sure that the amplitude frequency shape and pulse width are all consistent from cylinder to cylinder Look for abnormalities in the section of the waveform that corresponds to specific components Reference Waveform VEHICLE INFORMATIONS MAX 170 V arc over Or DUR 2 07 ms ignition YEAR 1987 DWEL Tags voltage MAKE Chrysler oe MODEL _ Fifth Avenue 100v ENGINE 5 2L 5y Hf spark or bum Leh FUELSYS Feedback C
148. tion temperature Storage temperature Relative Humidity Temperature Coefficient Max Voltage between any input and Ground Max Input Voltage GMM Basic DC Accuracy Bandwidth Max Sample rate Graphing Multimeter Display Counter Display Reference Waveform PC interface Power requirements Battery Life Size H x W x D Safety amp design 32 F to 104 F 0 C to 40 C 4 F to 140 F 20 C to 60 C 0 to 80 at 32 F to 95 F 0 C to 35 C 0 to 70 at 32 F to 131 F 0 C to 55 C Nominal 0 1 x Specified Accuracy C lt 18 C or gt 28 C lt 64 F or gt 82 F 300 V 300 V 0 3 DC to 5 MHz 3dB 25 Mega sample second 5 000 count 280 x 240 pixels active area with backlit EL 51 Waveform USB version 1 1 Rechargeable Battery External AC to DC Power Adaptor 4 Hours with backlit off 9 06 x 4 72 x 1 97 230 x 120 x 50 mm CAT II 300 V per IEC 1010 1 UL 3111 1 and C22 2 No 1010 1 Accessory User Manual AC to DC Power Adaptor Battery Charger Shielded Test Leads Ground Leads for Shielded Test Leads Alligator Clips 1ea 1ea 2 ea red and yellow 2 ea black 3 ea red yellow and black Back Probe Pins Secondary Pick up Inductive Pick up Soft Carrying Case USB Interface 3 ea red yellow and black lea lea 1ea Cable and Software Optional 1 ea Current Probe
149. to see There are many vehicle problems that can occur that really require a DSO or combination DSO and DMM to diagnose accurately 1 2 VEHICLE SERVICE MANUALS This instrument tells how to hook up it to the selected vehicle components to be tested However it is strongly recommended that you consult the manufacturer s service manual for your vehicle before any test or repair procedures are performed in order to get the color of the wire or the PCM s pin number from a wiring diagram For availability of these service manuals contact your local car dealership auto parts store or bookstore The following companies publish valuable repair manuals Mitchell International 14145 Danielson Street Poway CA 92064 Tel 888 724 6742 Haynes Publications 861 Lawrence Drive Newbury Park CA 91320 Tel 1 800 442 9637 Motor Publications 5600 Crooks Road Suite 200 Troy MI 48098 Tel 1 800 426 6867 Helm Inc 14310 Hamilton Avenue Highland Park MI 48203 Tel 1 800 782 4356 2 SAFETY INFORMATION ABNARNING READ SAFETY INFORMATION BEFORE USING THIS MANUAL This instrument is designed to be used only qualified personnel who are properly trained skilled professional automotive technicians It is assumed that the user has a thorough understanding of vehicle systems before using this instrument To use this instrument safely it is essential that operating and servicing personnel follow both generally accepte
150. ts the sensor s signal amplitude e Symptoms OBD II DTC s P0500 P0503 Inaccurate speedometer improper transmission shifting problems affecting ABS and cruise control e Test Procedure 1 Raise the drive wheels off the ground and place the transmission in drive 2 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 3 With KOBD Key On Being Driven monitor the VSS output signal at low speed while gradually increasing the speed of the drive wheels 4 Use the Glitch Snare mode to detect spikes and dropouts 6 20 e Reference Waveform VEHICLE INFORMATION YEAR 1988 MAKE Nissan Datsun bh Atle batalla hala la MODEL 300 zx non turbo th i AEN AAA f ENGINE 30L ov tha i l 4 fd I Hejit i j L l hj FUELSYS Multiport Fuel Injection my WY i WU a PCM_PIN 12 Wht wire at the instrument cluster J JRRD DIED EHD a Y STATUS KOBD Key On Being Driven AC signal Amplitude amp Frequency RPM 1500 ENG_TMP Operating Temperature VACUUM 20 In Hg uk we ee ms MILEAGE 57782 The amplitude and frequency increase with vehicle speed Vehicle Speed Sensors make waveforms whose shapes all look and behave very similar Generally the oscillations the ups and downs in the waveform are very symmetrical at constant speed Troubleshooting Tips If the amplitude is low look for an excessive air gap between the trigger wheel and the pickup If the amplitude
151. tter understanding of which signal types use which critical characteristics to do their electronic communication The above rules work very well and hold up in most cases but there are exceptions to its rules Not many but a few It may come as no surprise to some that serial data signals are the most complex signals in the vehicle They use all 5 critical characteristics to communicate with Thus they take a special analyzer to decode them one very familiar to most technicians the scan tool 3 4 SIGNAL PROBING WITH AN OSCILLOSCOPE The engine compartment of a running vehicle is a very unfriendly environment for automotive signals to live Temperature extremes dirt and corrosion and electrical leaks or noises from the high voltage pulses generated from a typical ignition system can produce interference that can contribute significantly to the cause of many driveability problems When you are probing components sensors and circuits be aware that the electrical noises from today s high output ignition systems can produce an RF energy that is similar to a radio station Since oscilloscopes are so sensitive this interference can actually override the signals you are trying to capture and give you a false reading on the display 3 2 To minimize this possible interference with the oscilloscope keep these tips and suggestions in mind E Most interference will be picked up by the oscilloscope test leads e Route the test leads away from
152. tween the peaks indicates a faulty injector driver in the PCM 6 35 PNP Type Injector e Theory of Operation A PNP type injector driver within the PCM has two positive legs and one negative leg PNP drivers pulse power to an already grounded injector to turn it on Almost all other injector drivers NPN type are opposite They pulse ground to an injector that already has voltage applied This is why the release spike is upside down Current flow is in the opposite direction PNP type drivers can be found on several MFI systems Jeep 4 0 L engine families some pre 1988 Chrysler engine families a few Asian vehicles and some Bosch vehicles in the early 1970s like the Volvo 264 and Mercedes V 8s The injector on time begins where the PCM switches power to the circuit to turn it on The injector on time ends where the PCM opens the control circuit completely Symptoms Hesitation on throttle tip in rough idle intermittent stall at idle poor fuel mileage emissions test failure low power on acceleration e Test Procedure 1 Connect the CH A lead to the injector control signal from the PCM and its ground lead to the injector GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System enters closed loop Verify this by reviewing the O2 sensor signal if necessary 3 Shut off A C and all other accessories Put vehicle in park or neutral Rev the engine sl
153. u follow the manufacturer s instructions and you look at the output voltage from each of the wheel speed sensors They all appear to be in tolerance and the manufacturer s fault tree recommends you to replace the ABS computer Unfortunately the ABS computer on this vehide is embedded in the master cylinder so you must replace everything The worst thing is the problem still exists even after you complete all of the work Normal ABS Signal Most of the signal shown above is visible to scan tools DSOs and DMMs Ia Faulty ABS Signal However the faults shown above are not visible to scan tools and DMMs They are only visible to DSOs 1 1 If you had a DSO you could look at the output signal from each of the wheel speed sensors From this you would have discovered that the left rear wheel speed sensor had some very fast aberrations that caused the ABS computer to act strange You replace the left rear wheel speed sensor to cure the problem The scan tools missed this problem because no trouble codes were set and the computer communication bus was too slow to pick up the spikes The DMMs missed this problem because it averaged the sensor signals and could not see the fast abberations Scan tools and DMMs sample very slow when compared to DSOs DSOs are typically more than a few hundred thousand times faster than scan tools and more than 1 000 times faster than DMMs There are many examples of vehicle signals that DMMs and scan tools are unable
154. ulated in acceleration modes Look for pulses that are a full 5 V in amplitude Look for the proper shape of the waveform in terms of consistent square corners and consistent vertical legs e Troubleshooting Tips Possible defects to watch for are runted shortened pulses unwanted spikes and rounded off corners that could all have the effect of garbling an electronic communication causing a driveability or emissions problem The sensor should be replaced if it has intermittent faults 6 30 Differential Pressure Feedback EGR DPFE Sensor e Theory of Operation An EGR Exhaust Gas Recirculation pressure sensor is a pressure transducer that tells the PCM the relative pressures in the exhaust stream passages and sometimes intake manifold It is found on some Ford EEC IV and EEC V engine systems Ford calls it a PFE Pressure Feedback EGR sensor when the sensor outputs a signal that is proportional to the exhaust backpressure Ford calls it a DPFE Differential Pressure Feedback EGR sensor when the sensor outputs the relative difference in pressure between intake vacuum and exhaust These are important sensors because their signal input to the PCM is used to calculate EGR flow A bad EGR pressure sensor can cause hesitation engine pinging and idle problems among other driveability problems and I M emission test failures The EGR pressure sensor is usually a three wire sensor One wire supplies the sensor with 5 V via the
155. unction from dirt or oil interfering with the light transmission through the rotating disk When dirt or oil enters into the sensitive areas of the sensors no starts stalls or misfires can occur Magnetic Vehicle Speed Sensor VSS Theory of Operation The vehicle speed sensors provides vehicle speed information to the PCM the cruise control and the speedometer The PCM uses the data to decide when to engage the transmission torque converter clutch lockup and to control electronic transmission shift levels cruise control idle air bypass engine cooling fan and other functions The magnetic vehicle speed sensors are usually mounted directly on the transmissions or transaxles They are two wire sensors and AC signal generating analog sensors They are very susceptible to Electromagnetic Interference EMI or RF from other electronic devices on the vehicle They generally consist of a wire wrapped soft bar magnet with two connections These two winding or coil connections are the sensor s output terminals When a ting gear a reluctor wheel rotates past this sensor it induces a voltage in the winding A uniform tooth pattern on the reluctor wheel produces a sinusoidal series of pulses having a consistent shape The amplitude is proportional to the rotating speed of the reluctor wheel The signal frequency is based on the rotational speed of the reluctor The air gap between the sensors magnetic tip and the reluctor wheel greatly affec
156. und clip on the fuel line of the first cylinder close to the injector and connect the adapter to the CH A 2 Connect the CH B to the TDC sensor signal output or HI Don t use the ground lead of the CH B test lead since the instrument is already grounded through the pickup adapter to the fuel line double grounding 3 Use the cursors to read the advance in degrees of the flywheel rotation Reference Waveform RPM 898 IA fi RPM 1689 ADV 15 i Hav 12 9 goe yg pe y i a NI IX NSN et Col pet ne peed Ax 1 NL Neti f i ATV Bt0V Auto f 15V 2 ma ATVB10V Auto f 15V 2ms Advance at idle Advance at 1689 RPM 6 70 AN WARNING Avoid Electrical Shock or Fire e Use only insulated probes test lead and connectors specified in this manual when making measurements gt 42 V Peak 30 Vrms above earth ground or on circuits gt 4800 VA e Use probes and test leads within ratings and inspect them before use Remove probes and test leads before opening case or battery cover e The instrument must be disconnected from all voltage sources before it is opened for any adjustment replacement maintenance or repair e Capacitors inside may still be charged even if the instrument has been disconnected from all voltage sources Discharge all high voltage capacitors before making resistance continuity or diodes measurements Cleaning Clean the instrument with a damp cloth and a mild detergent Do not us
157. ure E VACUUM 19 5 In Hg a Aio fo ank Se MILEAGE 40045 Look closely to see that the pulse width dwell changes when engine load and RPM changes Troubleshooting Tips Look for the drop in the waveform where the ignition coil begins charging to stay relatively consistent which indicates consistent dwell and timing accuracy of individual cylinder Look for a relatively consistent height on the arc over voltage or firing line A line that is too high indicates high resistance in the ignition secondary due to an open or bad spark plug wire or a large spark gap A line that is too short indicates lower than normal resistance in the ignition secondary due to fouled cracked or arcing spark plug wire etc Look for the spark or burn voltage to remain fairly consistent This can be an indicator of air fuel ratio in the cylinder If the mixture is too lean the burn voltage may be higher and if too rich the voltage may be lower than normal Look for the burn line to be fairly clean without a lot of hash which can indicate an ignition misfire in the cylinder due to over advanced ignition timing bad injector fouled spark plug or other causes Longer burn lines over 2 ms can indicate an abnormally rich mixture and shorter burn lines under 0 75 ms can indicate an abnormally lear mixture Look for at least 2 preferably more than 3 oscillations after the burn line This indicate a good ignition coil a good condenser on po
158. urrent causes the magnetic field to collapse partially creating a voltage spike similar to an ignition coil spike The PCM continues the Hold operation for the desired injector on time then it shuts the driver off by opening the ground circuit completely This creates the second spike Under acceleration the second spike move to the right while the first remains stationary If the engine is running extremely rich both spikes are nearly on top of one another because the PCM is attempting to lean out the mixture by shortening injector on time as much as possible Symptoms Hesitation on throttle tip in rough idle intermittent stall at idle poor fuel mileage emissions test failure low power on acceleration 6 34 e Test Procedure 1 Connect the CH A lead to the injector control signal from the PCM and its ground lead to the injector GND 2 Start the engine and hold throttle at 2500 RPM for 2 3 minutes until the engine is fully warmed up and the Feedback Fuel System enters closed loop Verify this by viewing the O2 sensor signal if necessary 3 Shut off A C and all other accessories Put vehicle in park or neutral Rev the engine slightly and watch for the corresponding injector on time increase on acceleration 1 Induce propane into the intake and drive the mixture rich If the system is working properly the injector on time will decrease 2 Create a vacuum leak and drive the mixture lean The injector on time will incre
159. urs when you perform floating measurements with grounding at different points INPUT A INPUT A rm z rye Rt INPUT B INPUT B Incorrect Grounding Correct Grounding Short Circuit by Grounding on Different Grounding at One Point Potentials Instrument Grounding for Measurements on the Ignition System For the instrument safety connect the COM input to engine ground before you perform measurements on the ignition system with the Capacitive Secondary Pickup To prevent ground loops connect all ground leads to the SAME engine ground 4 6 DISPLAY The instrument presents live measurement data in the form of Scope and GMM displays Temporary displays are used to display frozen and saved measurement data Menus are provided as a means of choosing instrument s measurement configuration To display the MAIN MENU while a measurement display is active press the MENU key at any time Menu Display When you press MENU key the instrument displays the MAIN MENU To select a menu option use the Four Way arrow keys to move the highlight bar to the desired item Then press F5 To exit the MAIN MENU and return to the previous setup press F1 During menu selection the bottom part of the screen is used to display the function key menu MAIN MENU COMPONENT TESTS SCOPE GRAPHING MULTIMETER VEHICLE DATA INSTRUMENT SETUP COMPONENT TESTS Leads to a series of predefined setups to test most common sensors an
160. veform from property YEAR 1995 operating TBI system at idle Hash is normal MAKE i Plymouth 1v Avg O2 voltage 526 mV ie MODEL Acclaim I itt A M N ENGINE 25L y f i k FUELSYS Throttle Body Fuel Injection PCM_PIN 41 BkGrn Wire i t l 4 f 7 STATUS KOER Key On Running iN RPM Idle ov j i ENG_TMP Operating Temperature Tr VACUUM 20 In Hg MILEAGE 4350 The maximum voltage when forced Rich should be greater than 800 mV The minimum voltage when forced Lean should be less than 200 mV The maximum allowable response time from Rich to Lean should be less than 100 ms NOTE For a Titania type O2 sensor change the vertical range to 1 V div Troubleshooting Tips The response time increases by aging and poisoning of the O2 sensor Peak to peak voltages should be at least 600 mV or greater with an average of 450 mV If the waveform is severely hashy look for a misfire caused by Rich mixture Lean mixture ignition problem vacuum leak to an individual cylinder injector imbalance or carboned intake valves IMPORTANT Don t use a scan tool at the same time you are analyzing the O2 waveform on the instrument The PCM may go into a different operating strategy when diagnostics are activated by the scan tool Dual 02 Sensor Theory of Operation Many vehicles utilize dual O2 sensors within the Feedback Fuel Control System Both O2 sensors provide an output voltage that represent the amount
161. voltage to a preset upper limit and varies the amount of the excitation current supplied to the field winding The field winding excitation is varied according to the battery s need for charge and ambient temperature Check the manufacturer s specs regarding the upper and lower limits of charging voltage permitted for the vehicle being checked The alternator s output voltage should be roughly 0 8 V to 2 0 V above the static battery voltage with the KOEO Key Off Engine Off 6 51 Symptoms No start low battery slow cranking Test Procedure Before performing the alternator output voltage test the battery s state of charge should be checked and a battery load test should be performed 1 Connect the CH A lead to the battery positive post and its ground lead to the battery negative post 2 Turn off all electrical loads and start the engine 3 Hold the engine at 2500 RPM for about 3 minutes and check the alternator s output voltage Reference Waveform VEHICLE INFORMATIONS namna TE PE YEAR 1986 est conducteq with engine z running and A C ofk MAKE Oldsmobile SECT EG EA eee ee I Se ER ES AT MODEL Toronado 12V i i ENGINE 3 8L FUELSYS Multiport Fuel Injection PCM_PIN CHA to Positive side of Battery 8v Normal voltage ranges are from 0 8 volts to 2 0 COM to GND volts above engine off j STATUS KOER Key On Running av i static battery voltage RPM lt 2500 ENG_TMP Operating Temper
162. w Sensor e Theory of Operation Digital Fast type MAF sensors can be found on GM s 3800 V 6 engine with the Hitachi sensor Lexus models and many others The Hitachi sensor has a square wave output in the 10 kHz range Voltage level of square waves should be consistent and frequency should change smoothly with engine load and speed Symptoms OBD II DTC s P0100 P0104 Hesitation stall low power idle problems excessive fuel consumption emissions failure Test Procedure 1 Connect the CH A lead to the sensor output or HI and its ground lead to the sensor output LO or GND 2 With the Key On Engine Running KOER use the throttle to accelerate and decelerate the engine Try different RPM ranges while spending more time in the RPM ranges that correspond to the driveability problem 3 Make sure that the amplitude frequency and shape are all consistent repeatable and accurate 6 28 4 Make sure that the sensor generates the correct frequency for a given RPM or airflow rate 5 Use the Glitch Snare mode to detect dropouts or unstable output frequency Reference Waveform VEHICLE INFORMATIONS MAX 605 YEAR 1990 MIN 0 00 V MAKE Buick BE MODEL Le Sabre i f i ENGINE 3 8L ov CAL ALCL A fen aw on a FUELSYS Multiport Fuel Injection Py T PCMLPIN Yel wire Ji rity STATUS KOER Key On Running re ne pi a cen ee a i RPM 2500 ENG_TMP Operating Temperature VACUUM 20 In Hg
163. wavers look for a bent trigger wheel or shaft If one of the oscillations look distorted look for a bent or damaged tooth on the trigger wheel IMPORTANT When troubleshooting a missing VSS signal check the fuse first If there is no power to the buffer there will be no square wave output If the fuse is good check the sensor first than a buffer mounted under the dash If you have a sine wave coming from the sensor but no square wave from the buffer don t assume the problem is in the buffer it may not be there because of a loose connector between the sensor and the buffer Optical Vehicle Speed Sensor VSS Theory of Operation The optical vehicle speed sensors are usually driven by a conventional cable and are found under the dash They are digital sensors and are not affected by electromagnetic interference EMI They generally consist of a rotating disk with slots in it two fiber optic light pipes a light emitting diode and a phototransistor as the light sensor An amplifier is coupled to the phototransistor to create a strong enough signal for use by other electronic devices such as the PCM or ignition module The phototransistor and amplifier create a digital output signal on off pulse Optical sensors are very susceptible to malfunction from dirt or oil interfering with the light transmission through the rotating disk When dirt or oil enters into the sensitive areas of the sensors driveability problems can occur and DTC
164. wly accelerate the drive wheels If the sensor to be tested is on a drive wheel raise the wheels off the ground to simulate driving conditions Key OFF Engine OFF KOEO 3 Use the Glitch Snare mode to detect spikes and dropouts 4 Compare ABS sensors on all wheels for similarities e Reference Waveform VEHICLE INFORMATION FREQ 416 Hz YEAR 1989 ABS wheel speed sensor MAKE Acura 20 f logged while driving 20 MPH MODEL Legend M i Il AN Hy ARSS Gad Fuel Injection HLM LAA UNA PCM_PIN Pos Grn Blu pin 13 Neg Brn pin 18 STATUS KOBD Key On Driven RPM 1200 ENG_TMP Operating Temperature VACUUM 18 In Hg MILEAGE 69050 10V Auto f 1 0V 10 ms Amplitude and Frequency increase with wheel speed Output signal should be stable and repeatable without distorted pulses Troubleshooting Tips If the amplitude is low look for an excessive air gap between the trigger wheel and the pickup If the amplitude wavers look for a bent axle If one of the oscillations looks distorted look for a bent or damaged tooth on the trigger wheel OQ2S Normal Zirconia e Theory of Operation An O2 sensor provides an output voltage that represents the amount of oxygen in the exhaust stream The output voltage is used by the PCM to adjust the air fuel ratio of the fuel mixture between a slightly Rich condition and a slightly Lean condition A zirconia type Oz sensor provides high output voltage a Rich condition
165. x 5 4 Dual Input Scope Operation PEE N EE A 5 5 Changing the Vehicle Data and Instrument Setup 5 6 Freezing Saving and Recalling Screens 5 7 Glitch Snare Operation 5 8 Tips for Noise Management s ss ssssssesssceesssesnsseensseeetaneetnssetsnsattnsonteeaneetnnsetsnsneennenteaneenanstsy 5 19 6 Automotive Diagnostics amp Applications 6 1 Component TES S cece essesesssteesseseeseecsssensansesneseessecnasencaneassnesensaessacencaneacsaeseesaeseasencansocsneseesaesaacencaneatsneeteys 6 1 6 2 Sensor Tests 6 3 Actuator Tests crccsereresesesetessessessseessesanseesnnsersascsasecansssas saeseasencansesanseesaesnasencantacsanseesanceasentaneatsnnsensaesnes 6 32 6 4 Electrical Tests cece eeetretereee ree eesteaneenseeseesnesaneaneeaseraeesaeeaneenteeseesmeeaneaneeaenseeseeaeentenseesmeeateaneass 6 48 6 5 Ignition Fegjg n a e E VE EEEE TN EENES AE E 6 57 6 6 gt Diesel Tests eikiisiieiii sisisi eaeko eiaa ianed eera ia i aa i a aai 6 68 7 Maintenance 8 Specifications Glossary Menu Overview 1 INTRODUCTION Vehicle manufacturers have helped you locate a driveability problem by designing Electronic Control Units with trouble code generating capabilities But the ECUs aren t perfect because they don t cover everything most glitches and intermittents On board diagnostic systems are engineered with fairy wide set limits for sensors actuators connectors and terminals When a component exceeds its limit consiste
166. y a bad alternator diode produces Peak to Peak voltages of more than 2 V Symptoms Overnight battery draining excessive AC current from alternator output flickering lights poor driveability e Test Procedure NOTE This test is made at the rear case half of the alternator and not battery The battery can act as a capacitor and absorb the AC voltage 1 Connect the CH A lead to the B output terminal on the back of the alternator and its ground lead to the alternator case 2 With the Key On Engine Off tum on the high beam headlights put the A C or heater blower motor on high speed turn on the windshield wipers and rear defrost if equipped for 3 minutes 3 Start the engine and let it idle 4 Make sure that pulses in ripple waveform are all about the same size and that pulses are not grouped into pairs 6 54 e Reference Waveform VEHICLE INFORMATIONS YEAR _ 1986 MAKE _ Oldsmobile 7 i i Yi NAahin AAAA MODEL Toronado 1 j JARI a ann Vy Vy yah ENGINE 384 I MA FUELSYS Multiport Fuel Injection PCM_PIN B post at alternator v vE Tested at idle with high beam and wipers l STATUS KOER Key On Running on and A C blower on high speed RPM Idle j ENG_TMP Operating Temperature i i VACUUM 18 In Hg 100 mV Avto f 0 04V 500 pe MILEAGE 123686 A bad alternator diode produces Peak to Peak voltages exceeding 2 V usually and its waveform will have humps that drop out and go much l
167. y quickly and let it drop back to idle again 6 Press the HOLD key to freeze the waveform on the display for closer inspection Reference Waveform VEHICLE INFORMATIONS 5 YEAR 1993 Beet MAKE Ford N ja MODEL Explorer i ee ENGINE 4 0L N ji t l l FUELSYS Multiport Fuel Injection d j N PCM_PIN 14 LtBlu Red wire amt Sh Be baton anal STATUS KOER Key On Running ov RPM Acceleration and Deceleration ENG_TMP Operating Temperature VACUUM 2 24 In Hg _ Aa ary meme MILEAGE 54567 Hot wire type MAF sensor voltage should range from just over 2 V at idle to just over 4 V at WOT and should dip slightly lower than idle voltage on full deceleration Vane type MAF sensor voltage should range from about 1 V at idle to just over 4 V at WOT and not quite back to idle voltage on full deceleration Generally on non Toyota varieties high airflow makes high voltage and low airflow makes low voltage When the sensor voltage output doesn t follow airflow closely the waveform will show it and the engine operation will be noticeably affected 6 26 Troubleshooting Tips If overall voltage is low be sure to check for cracked broken loose or otherwise leaking intake air ducts IMPORTANT 0 25 V can make the difference between a good sensor and a bad one or an engine that is blowing black smoke and one that is in perfect control of fuel mixture However because the sensor output voltages will vary substant

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