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10 - MDMotors

1. Older Software and Newer EFI SySIBITIB b nee Quicksilver DDT Scan Tool New Cartridge Tech Tips MerCruiser EFI II 1003 MerCruiser EFI Tool List Fuel System Tools Fuel pressure gauge set Adaptor fitting set MT337 300 Snap On Replacement seals for adapter fittings Snap On GM test port seal large MC Schrater test port seal small O ring TBI adaptor fitting with tire valve fitting Fuel line adaptor with nipple fitting Fuel line shut off tool MPI injector noid light Bosch connector GM TBI injector noid light Fuel line disconnect tool set 3 3 fuel supply at rail 5 46 fuel return plug at rail Portable 6 6 gal Fuel Tank Cole Parmer Digital PSIG Gage Stevens Instruments Gearcase Pressure Tester Fuel quality testing kit Fluke Pressure Vacuum Transducer Module Electrical System Tools DMT 2004 multi meter Set 10 Mega ohm impedance Clamp on ammeter probe for any standard DVOM DVA adaptor for any standard DVOM EFI 12v test light unpowered IAC noid light EFI test lead set GM style harness test leads Packard connector repair Kit Quicksilver Electrical Hardware Kit bullet connectors Quicksilver Crimping Pliers packard style Quicksilver Harness Seal Kit Snap on Terminal Tool Remote Starter Switch Rinda 94016 Ignition System Tools Kilo Volt meter Snap On Air gap spark tester single 1 2 inch gap Air gap spark tester 8 adjustable gaps Timing j
2. gt TO TRANSMISSION TEMP SWITCH YEL BLK gt T0 TRANSMISSION 76099 1 38 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 ECM Wiring Diagram MEFI 3 with GM EST Distributor V6 and Small Block V8 4 of 4 TO FUEL PUMP RELAY FUSE 440 ORN 2 RED ECM BAT FUSE 440 0RN gt TODLC DLC 15A CONNECTOR TO SYSTEMIIGNITION RELAY B 2 RED TO IGN INJ FUSE B ES 2 RED 902 MED 439 PNK IGNITION 150 BLK TO INJECTORS 902 RED TO FUEL PUMP RELAY TO IGNITION COIL TERM ECM GROUND ECM GROUND ECM GROUND FROM IGNITION IGNITION rid CONTROL 430 PUR WHT DIST REF HIGH 424 TAN BLK BYPASS 902 RED 453 RED BLK DIST REF LOW TEMP SENDER 121 WHT 208 LOAD ANTICIPATION TRANSMISSION 901 TAN B 585 TAN WHT DIE TENES 3 PNK E 29 AUDIO WARNING CONNECTOR HALVES CIRCUIT TAN BLU z J gt TO TEMP TAN E BLU TAN mem J gt YEL BLK m gt 76099 MerCruiser EFI II 0804 EFI SYSTEM COMPONENTS OPERATION 1 39 fYIg NVL U3MV4dud PCM 555 Charging Harness LHM NUg O3u 13A m LN TAN BLU oc ue BLU TAN JN ORA f YEL RED e ORA EBENEN PPL uis pa ee LAN BLK 0O BLK ANB
3. Fuel Injectors 1 8 Fuel Level 10 Fuel Pump Relay 11 IAC 12 Ignition Coils 1 8 13 Inputs 14 Input Output 15 Key B 16 Knock 1 17 Knock 2 18 Lube Oil Bottle 19 Main Power Relay MPR 20 MAP 21 MAT 22 Oil Pressure 23 Outputs 24 Paddle Wheel Sea Temp 25 Pitot 26 Port EMCT 27 Sea Pump 28 Starboard EMCT 29 Steering Angle 30 Tabs 31 Tach Signal 32 TP 33 Transom Harness 34 Trim UP Relay 35 Warning Horn EFI SYSTEM COMPONENTS OPERATION 1 5 Two Wire Sensors and IAT The following figure is the schematic of a 2 wire type sensor This sensor is basically a vari able resistor in series with a fixed known resistor within the computer By knowing the values of the input voltage and the voltage drop across the known resistor the value of the variable resistor can be determined The variable resistors that are commonly used are called thermis tors A thermistor s resistance varies inversely with temperature ECM TYPICAL SENSOR SENSOR SIGNAL 2 Wire Sensor Three Wire Sensors MAP TP and FP The following figure shows a schematic representation of a 3 wire sensor All 3 wire sensors have a reference voltage a ground and a variable wiper The lead coming off of the wiper will be the signal to the Engine Control Module ECM As this wiper position changes the signal voltage returned to th
4. Be careful when changing fuel system components gasoline is extremely flam mable and highly explosive under certain conditions Be sure that ignition key is OFF DO NOT smoke or allow sources of spark or flame in the area while changing fuel fil ters Wipe up any spilled fuel immediately Make sure that no fuel leaks exist before closing engine hatch DO NOT operate engine without cooling water being supplied to seawater pickup pump or pump impeller will be damaged and subsequent overheating damage may result NOTICE BEFORE proceeding refer to Precautions Disconnect battery cables from battery Remove fuel line from outlet side of boost pump or from inlet side of water separating fuel filter 3 Install Fuel Pressure Connector 91 18078 to boost pump or water separating fuel filter and reinstall fuel line Tighten connector and fuel line securely ND 3 4 DIAGNOSTICS MerCruiser EFI II 1003 4 Connect fuel pressure test gauge 0 15 psi to connector 5 Reconnect battery cables start engine and run at 1800 RPM If engine will not start crank engine to obtain reading 6 Fuel pressure should be within specifications 7 9 psi If not replace fuel pump NOTE If the screen on the inlet side of the boost pump is clogged the boost pump pressure will be low 77645 a Fuel from Tank b Fuel Boost Pump c Water Separating Fuel Filter d Fuel Cooler e Install Fuel Fitting
5. Smartcraft Audio Available SE qo Steer CKT Hi 100 Short or high voltage Steer OKTLo 100 CKT Or TPS1 CKT or Un CKT or Range 100 Open or high voltage 5 VDC PWR Low 4 Yes 2Bp min 90 Short or low engine may not start MAT Sensor Hi Yes 2Bp min 90 9 default to 32 degrees F h MAT Sensor Lo Yes 2Bp min 90 gt or default to 32 degrees F Shift Switch 5 2 Bp min Open Circuit NOTE If any 5v sensor becomes shorted to ground the engine will not start If the engine is operating when the short occurs the engine may stop operating and will not start NOTE GM EFI ignition system failure open or shorted driver will flag EST 1 fault NOTE TPS must see 5 throttle then back to 0 to flag IAC fault NOTE 3 2 wire sensor open will read sensor Hi on scan tool NOTE 4 VDC PWR Low if shorted or no voltage engine will not start if VDC PWR voltage falls velow 22 volts will set sensor faults NOTE 5 Shift Switch will activate code when engine rpm are above 3500 rpm and 40 load MerCruiser EFI II 1003 EFI SYSTEM COMPONENTS OPERATION 1 17 Manifold Vacuum Pressure Reference Chart Manifold Manifold Vacuum Absolute Pressure Vacuum Absolute Pressure ya us 5 7 2 sa 8 s 4 s s 93 2 mr ws 2 1 2 84 1 9 3 4 34 1 2 3 4 82 4 32 4 80 6 10 1 4 30 7 3 1 4 78 9 4 3 1 2 77 2 3 3 4 75 5 7 2 41 4 10 45 72 0 11 1 2 22 1 2 703 4 3
6. 7 Fuelline s should be installed free of stress and firmly secured to prevent vibration and or chafing MerCruiser EFI II 1003 GENERAL INFORMATION 4 3 8 Sharp bends in fuel lines should be avoided 9 Aflexible fuel line must be used to connect fuel supply line to fuel inlet fitting on engine to absorb deflection when engine is running SPECIAL INFORMATION ABOUT ELECTRIC FUEL PUMPS ACAUTION The electric fuel pump and factory installed water separating fuel filter have been carefully designed to function properly together Do not install additional fuel filters and or water separating fuel filters be tween fuel tank and engine The installation of additional filters may cause e Fuel Vapor Locking e Difficult Warm Starting e Piston Detonation Due to Lean Fuel Mixture e Poor Driveability SPECIAL INFORMATION FOR ALL GASOLINE ENGINES Avoid gasoline fire or explosion Gasoline is extremely flammable and highly explosive under certain conditions NEVER use gasoline as a cleaning solvent IMPORTANT The following information is provided to ensure proper installation of brass fittings or plugs installed into fuel pump or fuel filter base e Use 592 Loctite Pipe Sealant with Teflon on threads of brass fittings or plugs DO NOT USE TEFLON TAPE e Brass fittings or plugs should first be threaded into fuel pump or fuel filter base until finger tight e Fittings or plugs should then be tighten an additional 1 3
7. 15 19 ft 4 6 5 8 m 0000 120mm DIESEL ENGINES Cable Length Cable MES 4 3 4 6 ft erum a e Two cables of specified gauge required for positive and two required for negative MerCruiser EFI II 1003 GENERAL INFORMATION 4 9 With the old battery cable recommendation the negative and the positive battery cables were measured separately and then select the correct cable gauge to fit the length measured for each This was OK if they were both the same length It did not work well if there was a battery switch installed in the positive battery cable between the engine and bat tery Then the positive cable had to use a much larger gauge than the negative did In the example below this would have meant the shorter 36 in 91 4 cm length negative would have used a 4 25mm gauge cable The longer 228 in 579 1 cm positive cable would have used 0000 120mm gauge EXAMPLE A person measures 36 in 91 4 cm length of negative cable between engine and battery They measure 108 in 274 3 cm of positive cable between the engine and the battery switch and 120 in 304 8 cm between the battery switch and battery Add 36 in 91 4 cm 108 in 274 3 cm 120 in 304 8 cm 264 in 670 5 cm divide by 2 132 in 335 3 cm or 11 ft 3 4 m So BOTH the negative AND positive battery cable use the 00 70mm gauge cable By using the same gauge battery cable 00 7
8. 6 2L ECM 555 MPI Cool Fuel MerCruiser 320 EFI style intake plenum Keihin injectors Black Scorpion Pink 30 207 807952 1 Regulator on fuel cooler No ring on 5 7L amp 6 2L hose fitting 377 Scorpion Bravo amp Ski V8 5 0L 5 7L 6 2L ECM 555 MPI Gen 3 Cool Fuel GM MPI intake GMEFI system 5 0L MPI 350 Mag None 42 5 288 892681 Regulator in top of Gen 3 Cool Fuel Module MX6 2 Models V8 8 1L PCM 555 MPI Cool Fuel GM intake plenum injectors V8 496 Mag Blue Brown 43 296 861126 1 Regulator on fuel cooler Green ring on 8 1S Models hose fitting V8 8 1L PCM 555 MPI Gen 3 Cool Fuel GM intake plenum injectors V8 496 Mag None 42 5 288 892681 Regulator in top of Gen 3 Cool Fuel Module 8 1S Models e MEFI 1 2 3 ECM Fuel Regulator Identification Engine Color System Regulator Model Code psi kPa P N Comments V8 5 7L MEFI 1 TBI VST Non Gen engines GM TBU 350 Mag EFI Unknown 12 82 None Regulator in TBU See SB 94 8 Ski V6 4 3L V8 5 0L 5 7L MEFI 1 TBI VST Non Gen and Gen engines GM TBU All V6 EFI all Unknown 30 207 852955 Regulator in TBU V8 EFI models V6 4 3L V8 5 0L 5 7L MEFI 1 3 TBI Cool Fuel engines GM TBU All V6 EFI all Unknown 30 207 852955 Regulator in TBU V8 EFI models V8 5 7L MEFI 1 MPI VST Non Gen engines Keihin injectors 350 Mag MPI Unknown 43 296 806808 2 Regulator on the fuel rail Bravo Ski V8 5 7L MEFI 1 MPI
9. If there are no faults and no observable symptoms then troubleshooting is finished METUO eer Check Il IV VI Verify that the battery is fully charged and is of sufficient capacity for the engine being tested If necessary substitute a known good battery Check the battery cable connections Make sure they are clean and tight If present discard wing nuts and replace with corrosion resistant hex nuts A corrosion resistant toothed washer should be installed between the battery terminal and the cable end stack up must be battery terminal washer cable nut Make sure the cable connections are tight at the starter solenoid and that the block fuse on the starter solenoid if present is tight and its through bolt is not loose Also make sure the ground stud is not loose in the engine block and that its nut is tight If there is any doubt about the mechanical condition of the engine perform a compression test Make sure the safety lanyard is correctly installed and that the customer understands the cor rect starting procedure Check that all grounds are clean and tight If the negative battery cable is connected to the ground stud that does not contain all of the EFI and engine wiring harness ground leads con sider moving the negative battery cable to that ground stud Unplug and inspect the main harness 10 pin connector between the engine and boat har nesses If there is any doubt about the boat harness substitute a shop ha
10. The Amp hour rating is used outside the USA and Canada GASOLINE ENGINES Minimum Required Engine CID L Cranking Battery Size 375 cca or 475 mca or 90 Ah 450 cca or 575 mca or V8 Carb 90 Ah V8 550 V8 Carb 700 V8 120 Ah 600 cca or 750 mca V8 Carb i or 150 Ah All EFI and MPI 750 cca or 950 mca Models or 180 Ah DIESEL ENGINES 750 cca or 950 mca or 180 Ah 4 8 GENERAL INFORMATION MerCruiser EFI II 1003 Battery Cables Length and Size NOTE Battery should be located as close to engine as possible 1 Select proper size positive and negative battery cables using the chart 1 Add the positive and negative cable lengths together 2 Divide by 2 to obtain the average cable length IMPORTANT Terminals must be soldered to cable ends to ensure good electrical con tact Use electrical grade resin flux solder only Do NOT use acid flux solder as it may cause corrosion and a subsequent failure IMPORTANT Tapered post connectors with wing nut connections can be used The tapered posts must be used for the engine battery cables The wing nut connections should be used only for the power trim pump and accessories It is recommended that the wing nuts be replaced with regular nuts to ensure that the connections are tightened securely GASOLINE ENGINES Cable T Cable d 7 1 2 9 1 2 ft 2 3 2 9 m Lu 9 1 2 12 ft 2 9 3 7 m 12 15 ft 3 7 4 6 m
11. VST Gen engines Keihin injectors 350 Mag MPI Unknown 43 296 806808 2 Regulator on fuel rail Bravo V8 5 7L MEFI 1 MPI Cool Fuel on Starboard side Gen engines Keihin injectors Black Scorpion Unknown 43 296 808062 1 Regulator on fuel rail Ski 5 7L 1 28 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 e MEFI 1 22 3 ECM Fuel Regulator Identification Contd Engine Color System Regulator Model Code psi kPa P N Comments V8 5 7L MEFI 1 MPI Cool Fuel on Port side Gen engines Keihin injectors 350 Mag MPI Pink 30 207 807952 1 Regulator on fuel cooler No ring on hose Bravo Inbrd Ski fitting Black Scorpion Ski V8 5 7L 6 2L MEFI 2 3 MPI Cool Fuel on Port side Gen engines Magneti Marelli injectors 350 Mag MPI Pink 30 207 807952 1 Regulator on fuel cooler No ring on hose Alpha Bravo fitting Inbrd Ski and MX 6 2 MPI Bravo Inbrd V8 5 7L 6 2L MEFI 3 MPI Cool Fuel on Port side Gen engines Keihin injectors Black Scorpion Pink 30 207 807952 1 Regulator on fuel cooler No ring on hose 5 7L amp 6 2L fitting V8 7 4L L29 MEFI 2 3 MPI Cool Fuel GM MPI intake plenum injectors 7 4L MPI Blue Brown 43 296 861126 1 Regulator on fuel cooler Green ring on hose Bravo amp Inbrd fitting GM regulator on the fuel rail does not operate or control fuel psi V8 7 41 MEFI 1 GM TBI Cool Fuel GM TBI intake GM TBU 7 4LX EFI Bra
12. the ECM is faulty When this test is completed make sure that you clear the DTC 22 from memory An intermittent MIL with no stored DTC may be caused by the following e Ignition coil shorted to ground and arcing at ignition wires or plugs e MIL wire to ECM shorted to ground e Poor ECM grounds Go to ECM wiring diagrams e Check for an electrical system interference caused by a sharp electrical surge Normally the problem will occur when the faulty component is operated e Check for improper installation of electrical options such as lights ship to shore radios sonar etc e Check that knock sensor wires are routed away from spark plug wires ignition system components and charging system components e Check for secondary ignition components shorted to ground or an open ignition coil ground coil mounting brackets e Check for components internally shorted to ground such as starters alternators or relays All Ignition Control IC module wiring should kept away from the alternator Check all wires from the ECM to the ignition control module for poor connections MerCruiser EFI II 1003 DIAGNOSTICS 3 19 EFI Troubleshooting Guide MEFI Systems Troubleshooting Flow Chart for MerCruiser EFI MPI Engines abbreviated A Diagnostic Trouble Code indicates that the ECM has sensed that the circuit in question has re corded a sensor value outside of its acceptable window for at least as long as its pre programmed time pe
13. 1 Replace sensor 13 0 Inspect circuit Repair or replace harness 13 1 Replace sensor 14 0 Inspect circuit Repair or replace harness 14 1 Replace sensor 15 0 Change propeller 15 1 Trim drive properly 15 2 Check rev limit 16 0 Inspect wiring harness Repair or replace harness 16 1 Check sensor for damage Replace seals or sensor 16 2 Tighten hose connection 17 0 Check for blockage in inlet and outlet water hoses 17 1 Inspect seawater pump water ports impeller and seals for damage Replace damaged parts 17 2 Replace thermostat 17 3 Replace seawater pump 17 4 Replace drive belt 18 0 Inspect circuit Repair or replace harness 18 1 Replace sensor MerCruiser EFI II 1003 ECM 555 System Engine Fault Quick Reference Chart cont 19 Steer CKT Hi or Lo 20 TPS1 CKT Hi or Lo 21 TPS1 Range Hi or Lo 22 Transmission Overtemp 23 Trim CKT Hi or Lo 24 VDC PWR Lo MerCruiser EFI II 1003 19 0 Loose connection corrosion open Hi or short Lo in circuit 19 1 Faulty sensor 20 0 Loose connection corrosion open Lo or short Hi in circuit 20 1 Faulty sensor 21 0 Worn or damaged sensor count reading over 990 for Hi under 45 for Lo 21 1 Short in transducer ground circuit 21 2 Worn bent or corroded throttle lever 22 0 Loose connection corrosion open Lo or short Hi in circuit 22 1 Faulty sensor 23 0 Loose connection corrosion open Lo or sho
14. 3 MPI Cool Fuel on Port side Gen 350 Mag MPI None 30 207 861260T Magneti Marelli Alpha Bravo Inbrd Ski and MX 6 2 MPI Bravo Inbrd V8 7 4L L29 MEFI 2 3 MPI Cool Fuel GM MPI intake plenum injectors 7 4L MPI Olive Green 43 296 802632 GM Bravo amp Inbrd Band on Tip V8 7 4L MEFI 1 GM TBI Cool Fuel GM TBI intake 7 4LX EFI Bravo Yellow Black 30 207 853998 GM 7 4L EFI Inbrd V8 7 4L 8 2L MEFI 1 MPI VST and Cool Fuel MerCruiser MPI intake 7 4L amp 8 21 White Tip 36 248 805225 1 Keihin MPI models V8 7 4L 8 2L MEFI 3 MPI Cool Fuel MerCruiser MPI intake 7 4L amp 8 2L None 43 296 861260T Magneti Marelli 7 4L amp 8 21 V8 8 2L MEFI 3 MPI Cool Fuel MerCruiser MPI intake HP500 EFI Unknown 43 296 849896 1999 UP GM V8 8 2L MEFI 3 Dual TBI Cool Fuel Super Charger intake GM TBU HP575 SCi Yellow Black 30 207 853998T 2000 UP GM MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 33 Engine Wiring Diagrams MEFI 3 MCM 5 0L EFI 5 7L EFI and 350 Mag MPI Engines 8 6 E ys 2 1 4 GRY 2 PUR 5 TAN BLU 4 RED PUR 6 BLK 1 YEL RED 7 LIT BLU 8 TAN 3 BRN WHT 10 76061 A Audio Warning Components C Charging and Starting Components 1 Oil Pressure Switch Alternator Ground Stud B Instrumentation Components Starter Circuit Breaker Starter Slave Solenoid Jumper Wi
15. Big Block T bolt Small Block Separate knock module SB 94 12 Separate knock module Separate knock module Integral knock module 2 channels Clear flood mode active even when Clear flood mode active even when Clear flood mode active even when Clear flood mode is only active when the engine is not being cranked the engine is not being cranked the engine is not being cranked the engine is being cranked Shift interrupt switch opens the Shift interrupt switch opens the Shift interrupt switch opens ECM Shift interrupt switch opens ECM white IC line no spark white IC line no spark J1 19 retards timing closes IAC 2 9 retards timing closes IAC VST fuel system VST or Cool Fuel System Cool Fuel System Cool Fuel System IAT added on TBI units MPI Cool Fuel models require Fuel rail buffering required Staggered injector firing eliminates fuel rail buffering need for fuel rail buffering 7 possible codes 7 possible codes 15 possible codes 23 possible codes Technician must differentiate Technician must differentiate Technician must differentiate Scan tool DDT differentiates between active amp logged codes between active amp logged codes between active amp logged codes between active amp logged codes MEFI 3 Advanced Features Warning system Low oil pressure high water temperature and low drive oil level general warning 1 or high transmission temperatur
16. C 24 05 mohms e Crankshaft Position Sensor A to B 23 2 mohms and B to C 23 21 mohms With software prior to level 091 a malfunction of the crankshaft position sensor or the camshaft position sensor will not set a fault With level 091 software if the camshaft position sensor is bad and does not send a signal to the PCM the engine will backfire and not start Stop cranking the engine when this occurs and then try to start the engine Operate the engine for 20 seconds to set faults The Audio Warning alarm will signal 2 beeps per minute The Smartcraft system monitor will show the check engine light 1 42 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 PCM 555 Fuel Injector Harness YEL BLK PNK PNK BLK PNK WHT i gee d d xd TEM m a 5 0 5 d cc m B yn i I m pe E Lie z a ve lj am I Fr a PNK 3 jx 2 LU u z gt W I x Box 7 lt j PNK WHT p gt UJ a Injector Harness To Engine Harness Connector b Individual Injector Connectors The fuel injectors receive fused 12 volt power from Splice 108 Pins J and K on the injector harness The PCM signals the injector to fire by pulling the 12 volts to ground and completing the circuit The normal resistance at 21 degrees C 70 degrees F is 12 5 ohms A malfunction in the fuel injector harness will set the fault of FINJ 1 8 Open or FINJ 1 8 Short When
17. Check continuity of the ground wire Diagnostic connector Pin A and Pin 1 of the 10 pin Connector Was continuity present Check continuity between Diagnostic connector Pin B and ECM connector A 12 Was continuity present Check continuity between Diagnostic connector Pin C and ECM connector A 5 Was continuity present Using the scan tool check for faults stored in the ECM Were any faults present Go to Step 7 Go to Step 8 Go to Step 9 Replace ECM Inspect and repair fault Re test system Repair or replace harness Re test system Locate and repair the open in the harness Re test system Locate and repair the open in the harness Re test system Locate and repair the open in the harness Re test system Go to appropriate symptom chart DIAGNOSTICS 3 31 555 System Engine Fault Quick Reference Chart This chart correlates with the fault list of the diagnostic tool After displaying the faults stored in a ECM the fault can be referenced on this chart for possible causes and checks to fix the problem The single circuit diagrams in SECTION 3A correlate most of these faults with the sensor circuit schematics to help locate wiring problems 1 ECT CKT Hi or Lo 2 ECT Coolant Overheat 3 EST 1 Open or Short 4 Fuel Injector 1 8 Open or Short 3 32 DIAGNOSTICS Possible Causes 1 0 Open Hi or Short Lo in harness wiring faulty connection 1 1
18. Connector 91 18078 at Either Location Fuel Fitting Connector 91 18078 Description Connects fuel pressure gauge to fuel system installed between fuel supply pump and VST unit MerCruiser EFI II 1003 DIAGNOSTICS 3 5 Checking for Restrictions Vapor Lock Problems in Fuel Delivery Systems 3 6 DIAGNOSTICS If there are any restrictions in the fuel delivery system the engine may experience vapor lock and other driveability problems Fuel supply problems can be checked by using a vacuum gauge on a water separating fuel filter fitting port Installing it on the inlet side will check the fuel tank to filter supply line and hardware anti siphon valve fuel fittings etc Installing it on the outlet side will check the supply line hardware and the filter If the outlet vacuum read ing is higher than the inlet reading the filter is clogged If both readings are high then inspect the fuel tank supply line and hardware Check for trash in the tank blocking the pick up clogged fuel filter screens on the end of pick up tubes in the tank clogged in line fuel filters blocked off fuel tank vent bent pick up tube dirt and debris in fuel fittings wrong size fuel fittings undersize connector fittings undersize fuel shut off valve passages etc undersize fuel line or a malfunctioning anti siphon valve Digital Vacuum Gauge T Fitting Clear hose can be used to check EFI for air uel Sy
19. Fuel line from boat s fuel tank b Water separating fuel filter c Electric fuel pump d Fuel cooler e Fuel pressure regulator f Return line to fuel filter g Water flow through cooler h Vent line to flame arrestor i Throttle body with 2 fuel injectors dummy fuel pressure regulator MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 25 Fuel Pressure Regulator Assembly The pressure regulator is a diaphragm operated relief valve with fuel pump pressure on one side and regulator spring pressure and intake manifold vacuum on the other The regulator s function is to maintain a constant pressure differential across the injectors at all times The pressure regulator compensates for engine load by increasing fuel pressure as engine vacu um drops If the pressure is too hi or low poor performance can result Fuel Rail Spring Pressure e S M A In Fuel Rail Vacuum Line To Intake Manifold Diaphragm 1 26 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 26 Cool Fuel System Fuel Pressure Regulators There are 3 different Cool Fuel fuel pressure regulators that are used in production If the wrong regulator is used on an engine that engine can have a problem with its fuel supply to the injectors When checking regulator pressure on MPI engines always remove the small black hose that goes to the regulator before the test This
20. Inductive Clamp MerCruiser EFI II 1003 Direct Voltage Adapter DVA Optional Accessory P N 91 89045 PROCEDURE 1 Plug Direct Voltage Adapter into DMT2000A meter refer to Figure 1 3 Red lead plugs into the VOHz port and the Black lead into the COM port 2 Plug Test Leads into Voltage Adapter with Red lead into Red receptacle and Black into Black receptacle 3 Position rotary function knob to DC Voltage scale indicated by V 4 Read DC Voltage on DMT2000A Display Figure 1 3 DMT2000A with Direct Voltage Adapter and Test Leads Attaching Alligator Clips PROCEDURE 1 Screw alligator clips over ends of probes with Red to Red and Black to Black Refer to Figure 1 4 Attaching Alligator Clips 2 Tighten alligator clips finger tight Figure 1 4 Attaching Alligator Clips MerCruiser EFI II 1003 TOOLS amp TECH TIPS 2 9 Temperature Probe PROCEDURE 1 Plug small Thermocouple Plug into Thermo couple Probe with to and to refer to Figure 1 5 2 Plug Thermocouple Probe into DMT2000A with side to VOHz port refer to Figure 1 6 3 Position rotary function knob to TEMP position Use FUNCTION key to toggle between and F 4 Read temperature on DMT2000A Display Figure 1 5 Thermocouple Plug Figure 1 6 Thermocouple to Meter 2 10 TOOLS amp TECH TIPS MerCruiser EFI II 1003 Clamp On Current Probe Optional Accessory P N 9
21. Open Hi or Short Lo sensor 1 2 Water in the connector 2 0 Coolant leak 2 1 Restricted waterflow 2 2 Faulty seawater pump 2 3 Faulty thermostat 2 4 Faulty seawater pump 2 5 Worn or broken drive belt 3 0 Loose spark plug wire connection 3 1 Broken spark plug 3 2 Open or Short in harness wiring bad harness connection 3 3 Faulty coil 3 4 Water in connection 4 0 Open or short in harness wire bad harness connection or corroded terminals 4 1 Faulty fuel injector 4 2 12 volt fuel injector wire shorted to ground 4 3 Corroded harness terminals 1 0 Repair harness connection or cut in wire 1 1 Replace sensor 1 2 Dry connector and inspect for cracks or wear Replace 2 0 Inspect closed cooling system 2 1 Check for blockage in inlet and outlet water hoses 2 2 Inspect seawater pump water ports impeller and seals for damage Replace damaged parts 2 3 Replace thermostat 2 4 Replace seawater pump 2 5 Replace drive belt 3 0 Verify spark plug boot firmly connected 3 1 Inspect spark plug for damage Replace 3 2 Inspect coil harness Repair or replace 3 3 Replace coil 3 4 Dry connector and inspect for cracks or wear Replace 4 0 Inspect fuel injector harness Repair or replace 4 1 Replace fuel injector 4 2 Inspect fuel injector harness Repair or replace 4 3 Inspect fuel injector harness Repair or replace MerCruiser EFI II 1003 ECM 555 System Engine Fault Qu
22. RED PPL m n 1 RED PPL ii T3 L ri i YALYVLS YOLVNYSLIV ldd d3H HdMOd 2 m g U U YEL BLK BLK 7 E i 4 OLIMS NOISSIIN SNVHL JIN 3 23 NE NE a 1 BLK p s BLUTAN m 55 1 ucl LT BLU em 3H 13A c 3H 13JA aNnOH9 pRN WHT LL u mem LINDYID jm 3AV IS GRY ot 4 GRY GION310S 77671 1 40 EFl SYSTEM COMPONENTS OPERATION MerCruiser EFI 11 SSANYVH INOd ACGOHLVOYAWN T LON LON Hd N3S Wat HOWL xnv 0804 PCM 555 10 Pin Harness Circuit C B A 2000000 1002002200009 00000000000 9 10 12 3 14 15 18 9 10 17 12 13 14 15 16 12 13 1 15 16 17 18 19 20 21 17 18 19 20 21 22 23 24 17 18 19 20 21 22 23 24 22 23 24 25 26 27 28 29 30 31 32 BRN PNK SPLICE 102 se m lt I NC z EN sf amp ANALOG COOLANT TAN ic ABGDR MERC 77684 HARNESS a Tachometer Signal b Analog Coolant c 12 Volt Power d Audio Warning Alarm e Neutral Start Switch The 10 pin harness MERC harness is the connecting point between the Merc
23. VDC PWR voltage falls velow 22 volts will set sensor faults Knock Sensor 1 Hi Fuel Injector 3 5 2 8 2 Bp min 100 Fuel injector wire open Open es NOTE 5 Shift Switch will activate code when engine rpm are above 3500 rpm and 40 load MerCruiser EFI II 1003 EFI SYSTEM COMPONENTS OPERATION 1 15 555 Warning System Operation continued Smartcraft Audio Available Goes Mam Power Den Maint ower Redy Yes No N A Engine will not start Output Main Power Relay high Sensor 1 Input 2 Bp min High voltage or short MAP Sensor 1 Input E Open no visual on Sea Pump CKT Hi Sea Pump CKT Lo Sea Water Temp N Fuel Level 1 N STB EMCT CKT Hi N STB EMCT CKT Lo N STB EMCT CKT Overheat NOTE If any 5v sensor becomes shorted to ground the engine will not start If the engine is operating when the short occurs the engine may stop operating and will not start NOTE 1 GM EFI ignition system failure open or shorted driver will flag EST 1 fault NOTE 2 TPS must see 5 throttle then back to 0 to flag IAC fault NOTE 3 2 wire sensor open will read sensor Hi on scan tool NOTE VDC PWR Low if shorted or no voltage engine will not start if VDC PWR voltage falls velow 22 volts will set sensor faults NOTE 5 Shift Switch will activate code when engine rpm are above 3500 rpm and 40 load 1 16 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 1003 17 555 Warning System Operation continued
24. an understanding of the scan tool operation and limitations The technician should read the tool manufacturer s operating manual to become familiar with the tool s operation 1003 DIAGNOSTICS 3 11 General Service Precautions When Working On EFI Systems MerCruiser EFI Il The following requirements must be observed 1 2 Before removing any ECM system component disconnect the negative battery cable Never start the engine without the battery being solidly connected Never separate the battery from the on board electrical system while the engine is running Never separate the battery feed wire from the charging system while the engine is running 5 When charging the battery disconnect it from the boats electrical system 6 Ensure that all cable harnesses are connected solidly and that battery connections are thoroughly clean Never connect or disconnect the wiring harness at the ECM when the ignition is switched ON Before attempting any electric arc welding disconnect the battery leads and the ECM connector s When steam cleaning engines do not direct the steam cleaning nozzle at ECM system components If this happens corrosion of the terminals or damage of components can take place 10 Use only the test equipment specified in the diagnostic charts since other test equipment 11 1003 may either give incorrect results or damage good components All voltage measurements using a voltmeter
25. be cranked and started during the code clearing process If the voltage at the ECM drops below 6 9 volts for even the briefest period of time the ECM will reset and forget to clear the codes Install winky blinky to the DLC Key On Engine Off KOEO Turn the winky blinky to ON d While in Neutral cycle the throttle from 0 to 10096 and back to 0 e Turn the winky blinky to OFF for at least 5 seconds f Turn the ignition key to OFF for at least 20 seconds g Start and run the engine for at least 20 seconds h Turn the ignition key to OFF for at least 20 seconds i Verify that the codes were erased 2 MEFI 2 and 3 Codes can be easily cleared on these models because the engine does not have to be started Install winky blinky to the DLC Key On Engine Off KOEO Turn the winky blinky to ON While in Neutral cycle the throttle form 0 to 10096 and back to 0 Turn the ignition key to OFF for at least 5 seconds f Verify that the codes were erased MerCruiser EFI II 1003 DIAGNOSTICS 3 23 PCM ECM 555 Diagnostics A Fault indicates that the PCM ECMB55 has either sensed that the circuit in question has re corded a sensor value outside of its acceptable window or that a sensor value has gone outside its normal range For example h A circuit with an open or short would give a fault that is CKT or CKT LO This means that the sensor itself has failed with a
26. hose goes to the intake manifold or plenum and it has vacuum on it which causes the pressure to read lower at idle RPM By removing the hose the regulator s true pressure will be shown a Filter b Fuel Cooler Orifice c Pressure Regulator d Screw and Washer e Fuel Line 75708 There are 2 ways of identifying each regulator by looking at them By a colored paint mark on its mounting flange and by a small ring that is on the regulator s hose fitting ALL TBI ENGINES AND SMALL BLOCK MPI ENGINES Black Scorpion with Cool Fuel module on starboard side has a 43 PSI fuel system 30 psi 207 kPa Paint Mark Pink Ring on Regulator s Hose Fitting None ALL 7 4L MPI L29 ENGINES AND ALL 454 502 MAG EFI MPI ENGINES WITH MEFI 3 ECM S AND ECM PCM 555 ENGINES 43 psi 296 kPa Paint Mark Blue Ring on Regulator s Hose Fitting Green ALL 454 502 MAG MPI ENGINES WITH MEFI 1 ECM S 36 psi 248 kPa Paint Mark Yellow and Orange Ring on Regulator s Hose Fitting Black MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 27 Fuel Pressure Regulator Identification Revised Aug 6 2004 e ECM and PCM 555 Fuel Regulator Identification Engine Color System Regulator Model Code psi kPa P N Comments V6 4 3L V8 5 7L 6 2L ECM 555 MPI Cool Fuel GM MPI intake GMEFI system V6 4 3L V8 Blue Brown 43 296 861126 1 Regulator on fuel cooler Green ring on 5 0L 350 Mag hose fitting MX6 2 Models V8 5 7L
27. ignition timing and IAC motor count are restored 1003 EFI SYSTEM COMPONENTS OPERATION 1 13 ECM PCM 555 Engine Guardian Strategy amp Additional Guardian Sensors Engine Guardian is the focal point of the self diagnostic strategy of ECM PCM 555 It helps protect the engine from possible damage that could result from several faulty conditions The system monitors the sensors incorporated on the engine and if a malfunction is discovered a fault description is stored in the PCM and available power is normally reduced By ensuring engine output is at a low enough level the engine is better protected from thermally induced failures For example if an open or short is found in an exhaust manifold sensor available power will be reduced to 90 of total the warning horn will sound 2 beeps per minute and the MercMoni tor gauge SC1000 will display a warning lamp In an exhaust manifold overheat condition the maximum rpm will vary with the temperature of the manifold and could be limited to idle in extreme cases of overheating a continuous horn will sound and the SC1000 will display a warning lamp IMPORTANT Engine Guardian cannot guarantee that engine damage will not occur when adverse operating conditions are encountered Engine Guardian is designed to warn the operator of an adverse condition and to reduce power by limiting rpm in an attempt to reduce possible engine damage The boat operator is ultimately responsible for proper engine opera
28. incorporates Password protected EEPROM to prevent unauthorized reprogramming Footnotes 1 Except the 1998 350 Magnum MPI and the 129 7 4L MPI 2 If GM part number is any number other than 16210729 it is MEFI 1 software in a MEFI 2 case Only 16210729 is true MEFI 2 3 1996 models are all VST 1997 was a transition year 1998 models are all Cool Fuel 4 Scorpion models use EST ignition all other small blocks use the Thunderbolt hybrid ignition Il 123 JeSinaDJelN 001 LL NOIL VH3dO SLN3NOdINOO WALSAS 159 MEFI 1 GM 93 Software MEFI 2 GM 96 Software ECT voltage HIGH open 14 ECT HIGH or LOW open or short 14 ECT voltage HIGH open 14 15 ECT voltage LOW short 15 ECT voltage LOW short 21 TPS HIGH or LOW short or open 21 TPS voltage HIGH 21 TPS voltage HIGH 22 TPS voltage LOW 22 TPS voltage LOW 23 IAT HIGH or LOW open or short 23 IAT voltage HIGH open 23 IAT voltage HIGH ID 25 IAT voltage LOW short 2 3 33 MAP HIGH or LOW short or open 33 MAP voltage HIGH 33 MAP Golde qm 34 voltage LOW 34 voltage LOW 41 Open IC circuit 41 Open IC circuit 42 ICor bypass circui 42 ICor bypass circuit 42 C or bypass circuit 43 Knock circuit failure 43 Continuous knock detected 43 Continuous knock detected 44 Cannot detect knock activity 44 Cannot detect knock activity 45 Ignition coil driver circuit fault 51 Calibration checksum error 5
29. it knows how much based on the repeatability of airflow theory In reality the system is simple rugged and works extremely well But the ECM cannot compensate for changes in volumetric efficiency of the engine 1 2 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 1003 Abbreviations Crank Com oy DT E LC AM D D Digital Multimeter amp Tachometer Slave ECM Engine Control Module Switch Electronically Erasable Programmable Electronic Fuel Injection Throttle Position Sensor EMCT Exhaust Manifold Coolant Temperature EMI Electromagnetic Interference Vacuum MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 3 MEFI 3 ECM Input and Sensor Descriptions 1 Audio Warning Horn Buzzer 2 Discrete Switches Audio Warning 3 Dist For Ref RPM 4 ECT 5 6 Fuel Injectors 7 Fuel Pump 8 Fuel Pump Relay 9 IAC Motor 10 IAT 11 Ignition Control 1 4 EFl SYSTEM COMPONENTS OPERATION 12 Inputs 13 Knock Sensor 1 14 Knock Sensor 2 7 4L L29 15 Load Sw 16 MAP 17 Outputs 18 Serial Data DLC 19 System Relay 20 TP 21 V Reference 5 V Output to Sensors MerCruiser EFI II 1003 j PCM 555 03 Input and Sensor Descriptions MerCruiser EFI II 0804 Boost Fuel Pump Cam Position Sensor CMP CAN Line Cool Fuel Pump Crank Position Sensor CPS
30. of the air flow into the engine is the Hot Wire system A small wire is stretched across the air intake An electrical charge is run through the wire causing it to heat up As air flows over the wire it changes the temperature of the wire which changes its resistance and the resulting current flow The ECM can pick up this change in current flow and calculate the amount of air entering the system MerCruiser EFI II 1003 EFI SYSTEM COMPONENTS OPERATION 1 1 Another method of measuring the mass of the air flow into the engine is the vane type Mass Air Flow sensor A movable vane is mounted in protrudes into the air intake system The rush of intake air through the sensor causes the vane to be deflected The deflection is measured and a signal sent to the ECM NOTE The speed density system is more than accurate enough for our marine applications The additional reduction in emissions and the resulting increase in fuel economy with the Mass Air Flow system are negligible But when automotive manufacturers must meet emis sions standards they often have to take small improvements where they can find them Speed Density Operation The engine s RPM is easily determined from the REF HIGH signal on systems with EST igni tion or the timing signal from the Thunderbolt Distributor s hall effect sensor on small block MEFI 3 models To determine the density of the air in the intake manifold we need to know the intake manifold vacuum
31. or boat harness Isolate the gray carbureted or white EFI tach lead at the negative side of the ignition coil as described in the previous section step 4 If spark is now present the tach lead is shorted to ground in the engine harness boat harness or in the tach itself Disconnect the 4 pin connector from the ignition module Carbureted models if spark is now present the shift cut out switch is stuck on or shorted closed Replace the switch and retest EFI models if spark is now present the ECM is sending bypass voltage to pin B of the ignition module and it is not supposed to The EFI system will have to be diagnosed at this time as there is not a problem with the EST system MerCruiser EFI II 1003 MerCruiser EFI II 1003 Disconnect the 2 pin connector from the ignition module With the Key ON check for bat tery voltage at both the pink and brown terminals of the harness a If there is not battery voltage at the pink terminal replace the 2 wire harness as the filter is most likely blown open b Ifthere is not battery voltage at the brown terminal replace the ignition coil as the pri mary windings have most likely melted open because of a shorted tach lead c Reconnect the 2 pin connector to the ignition module when finished If spark is still not present remove the distributor cap and check the pickup coil for resist ance and short to grounds Resistance across the green and white leads must be 50
32. pattern of finely atomized fuel at the injector tip On throttle body systems fuel is directed into the bore of the Throttle Body Assembly and then it passes into the intake manifold On MPI models fuel is directed at the intake valve causing it to become further atomized and vaporized before entering the combustion chamber Throttle Body Injection TBI Fuel Injector 5 3 Needle Valve Nozzle Cap O Ring Valve Stopper Core O Ring Spring Housing Solenoid Coil Tape Bobbin O Ring Inner Collar Sleeve Terminal Connector Filter O Ring ELECTRICAL TERMINALS SIDE VIEW SCREW POLE PIECE COIL i RETURN SPRING FUEL INLET SEAL RING RENT SPRAY TIP UPPER O RING FUEL INLET FILTER ELECTRICAL CONNECTION SOLENOID WINDINGS SPRING BALL amp SEAT VALVE DIRECTOR PLATE JM LOWER O RING 9 NU SPRAY TIP Early 454 502 Models 7 4L 454 c i L 29 Models EFl SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 3 Fuel Injector Identification Revised Aug 6 2004 e ECM and PCM 555 Engine Injector Identification Engine Color System Injector Model Code psi kPa P N Manufacture Comments V6 4 3L V8 5 7L 6 2L ECM 555 MPI Cool Fuel GM MPI intake GMEFI system V6 4 3L V8 Neutral Tip 43 296 885176 GM 5 0L 350 Mag MX6 2 Models V8 5 7L 6 2L ECM 555 MPI Cool Fuel Me
33. service ECMs had the following items that will sound the alarm 1 MCM MIE Horn will sound if there is an active engine Diagnostic Trouble Code DTC that is occurring while the engine is running The horn will not sound a stored DTC Correcting the DTC malfunction will stop the horn 2 MCM MIE Horn will sound if the battery voltage to the ECM is low less than 9v for at least 5 seconds Using the throttle lever to increase engine rpm to get the alternator to put out more voltage will correct most low voltage problems V6 and V8 305 350 cid engines only Horn will sound if there is low fuel pressure for at least 5 seconds These engines have a fuel pressure sensor The EFI engines have the sensor in the throttle body unit and the MPI engines have the sensor located in the port fuel rail toward the rear of the engine Correcting the cause of the low fuel pressure will stop the horn A ECM checksums listed below have these additional alarms turned ON in them NOTE Later production and service replacement ECMs have these extra alarms turned off If the ECM checksum is different from the ones listed below the extra alarms in that ECM is turned OFF MOM 4 3L EFI ECM never had these extra alarms turned on 5 0L EFI With DO4B or D074 checksum MOM 5 7L EFI With D7ED or D798 checksum 350 MPI MCM 350 MPI Horizon MIE 350 MPI Ski MIE 350 MPI Inboard or MIE 350 MPI Horizon Inboard With E60
34. so may result in a misdiagnosis of the problem 3 10 DIAGNOSTICS MerCruiser EFI II 1003 Out of Range Sensors Scan Tool Use With Intermittents MerCruiser EFI II The scan tool allows manipulation of wiring harnesses or components with the engine not run ning while observing the scan tool readout The scan tool can be plugged in and observed while running the vessel under the condition when the Malfunction Indicator Lamp turns ON momentarily or when the engine driveability is momentarily poor If the problem seems to be related to certain parameters that can be checked on the scan tool they should be checked while running the vessel If there does not seem to be any correlation between the problem and any specific circuit the scan tool can be checked on each position watching for a period of time to see if there is any change in the readings that indicates intermittent operation The scan tool is also an easy way to compare the operating parameters of a poorly operating engine with those of a known good one For example a sensor may shift in value but not set a trouble code Comparing the senor s readings with those of the typical scan tool data read ings may uncover the problem The scan tool has the ability to save time in diagnosis and prevent the replacement of good parts The key to using the scan tool successfully for diagnosis lies in the technician s ability to understand the system he is trying to diagnose as well as
35. the external connections you will have to inspect several of the internal splices to verify that the damage is not also present at these locations 3 26 DIAGNOSTICS MerCruiser EFI II 1003 PCM ECM 555 Diagnostics continued XII Check for adequate secondary spark If an air gap tester is used make sure it will not ignite any fuel vapors that may be present in the bilge A KV meter can also be used to check for adequate secondary voltage Make sure the secondary wires are in good physical shape cor rectly routed and that the boots are not split at either end Remove the distributor cap ECM models and check for signs of moisture and carbon tracking Clearing Codes Faults are cleared with a scan tool only Refer to the appropriate DDT flow chart in the PCM ECM Technician Guide for appropriate menus IMPORTANT NOTES 1 When firing the ignition coil s under the Auto Self Test and Output Load Test screens A You must specify if the spark plugs are installed or not If the spark plugs are installed the PCM ECM will fire the coil s at the minimum dwell time to prevent it from actually sparking in the combustion chamber possibly igniting fuel vapors If the spark plugs are not installed the PCM ECM will fire the coil s at the maximum dwell time to allow for visible spark In either case the PCM ECM will monitor the 5 volt trigger circuits to attempt to detect whether the coil has fired NOTE lf using an air gap teste
36. vacuum leak and a possible fuel leak if the dummy regulator s diaphragm should fail Only the Cool Fuel regulator actually controls fuel rail pressure VIII Check all vacuum lines for splits kinks and proper connections The fuel regulator on all IX XI PCM ECM models must be connected to manifold vacuum The PCV valve is a calibrated air leak if it is missing or the incorrect valve is installed engine operation will be effected Check for any other additional air leaks in the induction system such as throttle body and intake manifold gaskets If the normal IAC 96 for the engine are known then any air leak will result in a lower IAC 96 than normal Unplug and inspect the PCM ECM A B and C connectors Make sure there are no PCM ECM pins bent over and that all of the correct pins are present Refer to the service manual charts for the pins used and not used Look for signs of tampering corrosion damage to the pin locking mechanisms melted insulation and any other evidence of shorts or other damage Unplug and inspect as many of the sensors and actuators as you can reasonably access Look for signs of tampering corrosion damage to the pin locking mechanisms melted insulation and any other evidence of shorts or other damage Based on the results of this inspection further inspection of the harness may be necessary Remember that there are many internal splices in the harness that may be damaged or defective If there is damage on
37. water to the engine 17 Properly ventilate engine compartment Avoid serious injury or death due to FIRE or EXPLOSION Ensure that engine compartment is well ventilated and that no gasoline vapors are present to prevent the possibility of a FIRE or EXPLOSION Ensure that no fuel leaks exist before closing the engine hatch 18 Start the engine Check for gasoline leaks around the fuel filter assembly If leaks exist stop the engine immediately Recheck filter installation clean spilled fuel and properly ventilate engine compartment Correct the leak Disconnect electrical connector at Cool Fuel Module Connect Digital Volt Ohm Meter DVOM to engine side of electrical connector Turn ignition switch to run position Verify that there is 12 volt battery power going to the Cool Fuel Module NOTE The fuel pump relay will only remain active for 2 3 seconds while the key is in the RUN position Checking Fuel Pressure 1 Connect fuel pressure gauge to shrader valve on fuel rail 2 Cycle key switch 2 3 times OFF to RUN position at 3 second intervals to reach maximum pressure 3 Verify that the pressure is within specification MerCruiser EFI II 0804 DIAGNOSTICS 3 39 4 If pressure is exceeds 44 psi a Replace Cool Fuel Module 5 If pressure is equal to or less than 40 psi a In Water Test 1 With vacuum gauge and fuel pressure gauges in place run the boat underway throughou
38. which we measure with the MAP Manifold Absolute Pressure sensor It is important to remember that a MAP sensor measures the manifold pressure above absolute zero like a barometer while a conventional vacuum gauge measures the manifold pressure below the current atmospheric pressure The use of the Manifold Absolute Pressure Sensor allows us to compensate for variations in atmospheric pressure due to weather and altitude chan ges A conventional vacuum gauge would not provide us with this needed information NOTE While the temperature of the air does affect its density not all engines use an IAT in take air temperature sensor If no IAT is present then the ECM assumes 75 degree Fahren heit for all density calculations If an IAT is present then the ECM can more accurately deter mine the air s density However the amount of correction the IAT adds is a relatively small amount approximately 10 maximum change in fuel flow In review our standard unmodified production engines flow a repeatable and therefore known amount of air at any specific engine rpm and manifold pressure With this knowl edge the ECM can be programmed to deliver the correct amount of fuel from the combination of the speed sensor distributor signal and density information from the MAP sensor It is often said that the speed density system runs in theory alone since the ECM doesn t really know how much air is flowing through the engine it is just assuming
39. 0 1500 ohms 750 850 preferred and the reading must be steady Resistance be tween the green lead and the distributor frame must be infinity and resistance between the white lead and the distributor frame must be infinity If any of these readings differ from specifications replace the pickup coil Verify that the timer core is still magnetic This is the part that rotates above the pickup Coll If spark is still not present you will need to false trigger the module to determine if it is opening and closing the primary circuit Proceed as follows a If still isolated reconnect the tach lead to the ignition coil Connect a voltmeter to the gray tachometer lead bullet connector near the ignition coil Set the meter to read DC volts Connect an air gap tester from the coil s secondary terminal to ground b Remove one of the ignition module mounting screws and loosen the other Rotate the module out from the distributor frame then retighten the loose screw Connect the positive lead from a 1 5 volt AA or similar battery to the ignition module s P terminal pickup coil terminal c With the key in the ON position note the voltmeter reading It must be battery voltage If not you didn t verify the coil primary windings are good or you didn t find the short to ground in the gray tach lead If the voltage is OK proceed d While observing the voltmeter momentarily connect the negative lead of the 1 5 volt battery to th
40. 0mm gauge in the example above for BOTH the negative and positive cable the longer length positive cable can use a smaller gauge cable than it would have if the negative and positive gauges were sized to their respective lengths Battery Testing Hydrometer Tests A fully charged battery will read between 1 225 and 1 280 at 80 Fahrenheit Readings of 1 225 and lower will require recharging amp retesting All cells should read within 30 points of each other You must correct the Hydrometer reading for Ambient Temperature Capacity Tests The Specific Gravity must be 1 225 or higher before continuing Variable Load High Rate Discharge Tester Recommended Discharge the battery with a load bank carbon pile set to 1 2 the CCA Rating or times the Amp Hour Rating for 15 Seconds at the end of the 15 second period the battery voltage must be 9 6 volts or higher Fixed Resistance This equipment has built in load for high rate discharge testing Follow equipment manufacturer s instructions regarding test period and meter readings Cranking Discharge Method With a Voltmeter attached to the battery Crank the engine for 15 seconds the battery voltage must be 9 6 Volts or higher at the end of the 15 second period Lower ambient temperature readings below 70 Fahrenheit will result in lower voltage readings 0 F 10 F 20 F 30 F 40 F 50 F 60 F 8 5v 8 7v 8 9v 9 1v 9 3v 9 4v 9 5v 4 10 G
41. 1 802650 IMPORTANT Refer to Users Guide supplied with Clamp On Current Probe for proper testing procedures PROCEDURE 1 Plug end of Clamp On Probe with side marked into VQHz port and side with to COM port refer to Figure 1 7 and Figure 1 8 Clamp On Probe to Meter 2 Position rotary function knob to DC Voltage scale indicated V 3 Read DC Voltage on DMT2000A Display Figure 1 7 Clamp On Probe EETASO1B ACIDC CLAMP ADAPTER Figure 1 8 DMT2000A with Clamp On Current Probe MerCruiser EFI II 1003 TOOLS amp TECH TIPS 2 11 P N 91 805747A2 Timing Tool for MerCruiser EFI Engines a Timing Tool b DLC Connector CODEMATE Marine EFI Code Reader Rinda CodeMate serves as both an EFI problem indicator and a spark timing service tool The de vice connects to the DLC in a matter of seconds and alerts the boat owner or technician when EFI problems are detected CodeMate allows diagnostic trouble codes DTC s to be read and when used with a timing light allows the technician to verify set the base ignition timing Available from Rinda Technologies Inc Chicago IL Telephone 773 736 6633 Fax 773 736 2950 Rinda 94008 Scan Tools Older Software and Newer EFI Systems Older scan tool software for the Quicksilver Digital Diagnostic Terminal DDT and MerCruiser Rinda scan tools will not be able to read the information coming from either the newer MEFI s or the ECM PCM
42. 1 Calibration checksum error 51 Calibration checksum error 52 EEPROM failure in ECM 61 62 EEPROM failure in ECM Fuel pressure sensor HIGH Fuel pressure sensor LOW NOTE Not every engine will use every possible code check the service manual for the codes used on a specific engine Footnotes 1 Signal lead shorted to power 2 Signal lead shorted to ground or open 3 Circuit s either open or shorted to ground 4 C grounded and or Bypass open or grounded Big elco EST ignition 7 Small block engines only with Thunderbolt distributor and coil 8 Reference 5V open or shorted to ground IMPORTANT On the L29 injector banks are 1 3 5 amp 7 and 2 4 6 amp 8 other MPI models should be 1 4 6 amp 7 and 2 3 5 amp 8 MEFI 3 and Audio Warning The MEFI 3 engine s Audio Warning system will sound the alarm differently and it has more items that will cause it to sound There is what is called a soft and a hard alarm 1 Soft Alarm Below 3000 rpm Horn on for 1 second off for 3 seconds on for 1 second off for 3 seconds etc 2 Hard Alarm Above 3000 rpm Horn sounds all the time Audio alarm sounds for the same malfunctions as MEFI 1 and 2 1 AMOM Low lube level in Gear Lube Bottle General 1 or MIE High Transmission fluid temperature General 2 2 MCM MIE Low engine oil pressure 3 MCM MIE Too high engine coolant temperature A Early production and
43. 4 68 6 7 D 7 2 11 3 4 20 3 18 6 12 1 4 16 9 12 1 2 15 2 5 1 2 63 4 12 3 4 13 4 5 3 4 61 7 11 7 6 a w or 31 S 1 18 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 1003 13 Vacuum Gauge vs MAP Sensor 100 90 E L 13 T 85 _ 25 12 80 t SELLINALLLLI DEEP L 21 70 z V 10 isl EHE 3 F 3L e 28 amp S tgal rr S55 16 9 T eo x 15 c c 5 p 90 rg a Fe DL 0 x fa 241 8 a40 12 0 6 Bo 35 L 10 L5 4 304 25 L 7 L 20 M 6 L 3 5 15 L4 T ot ott LLL TET TEEN TS LLLLLLELENE La 0 LO 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Hand Held Vacuum Gauge in Hg This graph is correct at Sea Level only MerCruiser EFI II 1003 EFI SYSTEM COMPONENTS OPERATION 1 19 Fuel Systems Diagrams Multi Port Injection With Vapor Separator Tank VST 73895R2 a Fuel line from boat s fuel tank b Water separating fuel filter c Supply pump mechanical or electric d Vapor separator tank e Fuel rail f Fuel injectors 8 g Fuel pressure regulator h Vacuum line to intake manifold i Return line to vapor separator tank 1 20 EFI SYSTEM COMPONENTS OPERATION MerCr
44. 4 to 2 1 4 turns using a wrench DO NOT OVERTIGHTEN e To prevent over tightening when installing a fuel line the brass fittings should be held with a suitable wrench as fuel line connectors are tightened securely 4 4 GENERAL INFORMATION MerCruiser EFI II 1003 meRCURY service bulletin No 2001 15 WARRANTY INFORMATION V SERVICE INFORMATION New Gasoline EFI MPI Engine Fogging Procedure Models All MerCruiser gasoline EFI and MPI engines produced in Stillwater NOTE This change does not apply to carbureted engines produced in Stillwater or Hi Per formance engines produced by Mercury Racing Change Follow this new fogging procedure when laying an engine up for storage Fogging Mixture In a 6 US gal 23 L remote outboard fuel tank mix 5 US gal 19 L regular unleaded 87 octane 90 RON gasoline 64 fl oz 1 89 L Mercury or Quicksilver Premium Plus 2 Cycle TC W3 Outboard oil 5 fl oz 150 mL Mercury or Quicksilver Fuel System Treatment and Stabilizer OR 1 fl oz 30 mL Mercury or Quicksilver Fuel System Treatment and Stabilizer Concentrate 2001 15 SEPTEMBER 2001 Printed in U S A 6 2001 Mercury Marine Page 1 of 2 MerCruiser EFI 11 1003 GENERAL INFORMATION 4 5 New Fogging Procedure 1 Disconnect and plug boat s fuel line from Water Separating Fuel Filter inlet 2 Connect remote outboard fuel tank with the fogging mixture to the inlet of the Water Separating Fuel Filter IMPORTANT If
45. 555 If you use the wrong software you will get an error message on the display of the DDT scan tool or you will get incorrect information from a MerCruiser Rinda scan tool Quicksilver DDT Scan Tool New Cartridge The DDT will need MerCruiser cartridge version 2 0 P N 91 803999 to read MEFI 3 ECM s This cartridge can also read data from Thunderbolt 5 ignition used on carbureted models See Service Bulletin 2001 2 A second cartridge will be required to read ECM PCM 555 control lers Order SmartCraft DDT cartridge version 1 3 P N 91 880118 003 2 12 TOOLS amp TECH TIPS MerCruiser EFI II 1003 Tech Tips MerCruiser EFI II The following Tech Tips are ideas that you may find useful 1 Cylinder Balance Test Tool Cable Tie P N 5469355 Cd 1 N Bullet Terminal P N 86 814434T 3 Cut Piece Vacuum Vent Hose P N 32 806173 79 Construct eight tools as shown above Insert a hose end into each spark plug wire tower on HVS distributor cap and insert bullet terminal end into corresponding spark plug wire boot Start engine By grounding each hose in turn with a 12v test light you will be able to tell if each cylinder is functioning Remote Starter Switch PN 91 52024A1 Probably the easiest way to attach the remote starter switch is to hook one lead to any convenient power source such as either side of the circuit breaker or the slave solenoid red purple terminal and the other lead to the slave
46. 850A 1 2 3 kit This kit comes with both size test port valve adapters and instructions on how to fit it to the older gauge kit 91 881833A 2 Fuel Pressure Gauge Kit Kit contains Adapter Kit and TBI Pressure Valve To update older 91 16850 1 A 2 0r A T Fuel Pressure Gauge Kits order the following HI 91 806901 TBI Pressure Valve TEN Allows older Gauge Kits to i connect to TBI engines 91 803135 Adapter Kit Allows older Gauge Kits to connect to either type of test port valve 1003 DIAGNOSTICS 3 1 Testing Mechanical or Electric Fuel Supply Pump used on VST models Precautions Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion Be careful when changing fuel system components gasoline is extremely flam mable and highly explosive under certain conditions Be sure that ignition key is OFF DO NOT smoke or allow sources of spark or flame in the area while changing fuel fil ters Wipe up any spilled fuel immediately Make sure that no fuel leaks exist before closing engine hatch DO NOT operate engine without cooling water being supplied to seawater pickup pump or pump impeller will be damaged and subsequent overheating damage may result NOTICE BEFORE proceeding refer to Precautions 1 Disconnect battery cables from battery 2 Remove fuel line from outlet side of mechanical or electric fuel supply pump
47. CM on J2 20 This signal tells the ECM if the switch is closed or open In neutral gear the neutral safety switch is closed signal grounded When shifting into gear the switch opens signal open When the transmission is shifted into gear the open signal causes the ECM to add a cali brated amount of bypass air with the IAC This is done to increase the load handling capability of the engine when going into gear on larger boats When shifting back into neutral gear the additional IAC bypass air is removed in an attempt to limit engine rpm flares The amount of IAC air used is constantly monitored by the ECM After the transmission is shifted and the engine has stabilized the ECM calculates an error band from the Moving Desired RPM mode and adjusts the Load Anticipation mode IAC count accordingly This allows the ECM to learn the best IAC bypass air position to use for shifting each particular boat NOTE The Load Anticipation mode is on MIE 454 502 cid inboard engines also Shift Switch Operation MerCruiser EFI II The Shift Switch is used on Alpha models only The switch is normally closed completing a circuit from the ECM s J2 9 terminal through the shift switch to ground When shifting the switch will open the J2 9 wire between the ECM and ground This will cause the ECM to go and lower the IAC motor count and retard the ignition timing to help the shifting When the shift switch is back in the normal position
48. D or EAED checksum MIE Black Scorpion With BB98 or BB42 checksum MCM 7 4L MPI or MIE 7 4L MPI Inboard With FE28 checksum MCM 454 MPI MCM 454 MPI Horizon or MIE 454 MPI Horizon Inboard With EBC4 check sum MCM 502 MPI or MIE 8 2L MPI Inboard With FO2D checksum 1 12 EFl SYSTEM COMPONENTS OPERATION MerCruiser EFI II 1003 Additional MEFI 3 ECM Features Moving Desired RPM Mode ECM s with Delphi 1623999 A Moving Desired RPM mode has been added to the MEFI 3 ECM This mode will increase the desired idle rpm to a calibrated set point according to the throttle position When the Throttle Position TP sensor is at the closed throttle setting the ECM will use Idle Air Control IAC and Ignition Control IC to maintain the calculated desired rpm This will make the tran sition from idle closed throttle to higher throttle settings smoother It will also help maintain constant low engine speeds from 700 to 1200 rpm At 5 or greater TP sensor setting the Moving Desired RPM mode is not active IMPORTANT An improperly adjusted throttle cable can cause the engine idle rpm to be higher than the normal 600 rpm even though the control throttle lever is back to the idle rpm position Load Anticipation Mode The Load Anticipation mode is used on MIE inboard and ski engines only The function is used to help inboard engines during shifting An electrical signal from the neutral safety switch on the transmission goes to the E
49. DDT MC Rinda MEFI Data Sheet PCM ECM 555 Data Log Sheet Rinda Scan Tool General Service Precautions When Working On EFI Systems Intermittent Faults EFI Troubleshooting Guide MEFI Systems PCM ECM 555 Diagnostics ECM 555 Troubleshooting Preliminary Checks Visual Physical Checklist ECM 555 On Board Diagnostic OBD System Chart ECM 555 System Engine Fault Quick Reference Chart Gen 111 Cool Fuel Module Diagnostics MerCruiser EFI II 0804 Testing Fuel System Pressure on EFI Throttle Body Injection Systems 91 881833A2 a Remove Fuel Line from Throttle Body Unit and Install Fuel Fitting Connector P N 91 806901 Connect Fuel Pressure Gauge Kit P N 91 881833 2 5 5 from 91 16850A7 to test system pressure Fuel Pressure Test Gauge Adaptor Fittings MerCruiser EFI II The following information is contained in revised Service Bulletin 97 24 1998 2000 MCM MIE 7 4L MPI L29 uses a different size and type of test port valve on it for checking the fuel pressure at the fuel rail The older Fuel Pressure Gauge Kit P N 91 16850A 2 will not attach to this valve A new kit has superseded this kit and it contains 2 fittings so it will fit both types of test ports and a TBI pressure valve to allow the gauge to connect to TBI engines Quicksilver will also sell an Adapter Kit that can be purchased to update the older 91 16
50. ENERAL INFORMATION MerCruiser EFI II 1003 Charging Guide 12 Volt Battery Recommended Rate and Time for Fully Discharged Condition Twenty Hour 5 10 20 30 40 50 Rating Amperes Amperes Amperes Amperes Amperes Amperes 50 Ampere Hours or 10 Hours 5 Hours ats 2 Hours pes ours Above 50 to 75 7 1 2 3 1 2 2 1 2 1 1 2 Above 75 to 100 59 Hours 10 Hours 5 Hours 3Hours 21 2 2 Hours Ampere Hours Hours Above 100 to 150 30 Hours 15 Hours Buc 5 Hours Vaid 3 Hours Ampere Hours Above 150 20 Hours 10 Hours 61 2 5 Hours 4 Hours Ampere Hours Hours nitial rate for constant voltage taper rate charger To avoid damage charging rate must be reduced or temporarily halted if 1 Electrolyte temperature exceeds 125 F 52 C 2 Violent gassing or spewing of electrolyte occurs Battery is fully charged when over a two hour period at a low charging rate in amperes all cells are gassing freely and no change in specific gravity occurs For the most satisfactory charging the lower charging rates in amperes are recommended Full charge specific gravity is 1 260 1 280 corrected for temperature with electrolyte level at split ring Battery Power as Affected by Temperature 80 27 100 32 0 0 18 20 29 74310 Power Watts Available Power Watts Required MerCruiser EFI II 1003 GENERAL INFORMATION 4 11 Wiring Colors for MerCruiser NOTE Colo
51. Elston Ave 655 Eisenhower Drive P O Box 9090 847 549 7600 Chicago IL 60630 Owatonna Minnesota 55060 Everett WA 98206 9090 847 247 2929 FAX 773 736 6633 800 533 0492 800 443 5853 847 549 1700 International FAX Fax 773 736 2950 Fax 800 283 5665 Kent More Tools SPX Corporation Stevens Instruments SPX Service Repair J tools 111 Greenwood Avenue 2300 Park Drive 29784 Little Mack Waukegan Illinois 60079 9375 Owatonna MN 55060 Roseville MI 48066 847 336 9375 800 344 4013 800 345 2233 Fax 847 662 6808 Fax 810 578 7375 2 2 TOOLS amp TECH TIPS MerCruiser EFI II 1003 QUICKSILV A Marine Parts amp Accessories Attention Dealers You know from your own marine service experience that outboard ignition systems are very noisy with lots of RFI interference Our new DMT 2000A Digital Tachometer Multi meter represents real breakthrough technology in the marine service industry It s the only meter on the marine market today designed to read accurately in high RFI environments The only meter that measures RPM on both 2 and 4 cycle marine engines while recording maximums and minimums simultaneously Give your service personnel the latest in innovative marine technology the DMT 2000A Digital Tachometer Mul ti meter from Mercury Marine Order today Complete the order form below and we guarantee that your marine service life will get just a little easier Replacement Components Hard carrying case 91 854014 1 User s
52. GENERAL The main concern of a boat s fuel system is safety this must be achieved through a technically sound installation and constant inspection The fuel system from the filler pipe to the fuel pump is the same in principle for all boats The fuel tank is an integrated component of the boat Refer to the special information on service and mainte nance which you have received from the tank manufacturer Only a few points related to function and safety are listed here Refer to boating standards NMMA ABYC etc and Coast Guard regulations for complete guidelines e All connections should be on the upper side of the tank e The drain plug at the lowest point on the tank serves to permit the removal of water and sediment e The filler pipe outer diameter should be at least 2 in 50 mm e The tank breather pipe must have an inner diameter of at least 1 2 in 13 mm and must be fitted with a swan neck to prevent water from entering the tank It is recommended that the exact route and length of the fuel lines be established at the first installation of the engine to prevent problems later in connecting them to the engine All fuel lines must be well secured The holes where the lines run through the bulkheads should be carefully rounded off or protected with rubber grommets This prevents damage to the lines from abrasion The following but not limited to the following additional fuel connection related points applying to all engi
53. M powers pin B4 which in turn pulls the MPR low The MPR powers the coils through Splice 105 and powers the engine for ignition p 2805 Ee 1 44 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 PCM 555 Coil Harness Circuit Q RED E e gt crn pruk d U 25 A UJ AU z U Pd D EF oH SPLICE SPLICE BRN PNK U A BLK BLU z PNK Q PUR BRN ea b BLK 77695 a Coil Harness To Engine Harness Connector b 1 And 8 Coil Connector c 3 And 6 Coil Connector d 5 And 4 Coil Connector e 7 And 2 Coil Connector There are 2 coil harnesses on the engine one for each side of the engine The harnesses are wired identically The signal wire color for coils 1 and 8 is BLU coils 3 and 6 is PUR 5 and 4 wire is GRN and 7 and 2 is RED The PNK wire is 12 volt power the BRN wire is 5 volt power and the BLK wire is ground If a possible problem is suspected in the ignition system check for faults once with key ON and once with engine running An EST Open will only register a fault in a key ON only state and an EST Short will only register with the engine operating A malfunction in the coil harness will set the fault of EST 1 8 Open or EST 1 8 Short MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 45 Gen Il Cool Fuel System System features e Single Integrated Module Filter pumps pressure regulator and cooler all in on
54. OTC replacement boot for DDT OTC 3305 30 OTC printer for DDT OTC 3285 OTC printer cable for DDT 25 pin serial port OTC 212536 OTC PC cable for DDT 9 pin serial port OTC 212535 Standard manifold vacuum gauge Locally available Mechanics stethoscope Locally available 3 of 5 32 I D clear vinyl hose with a 5 32 Tee Locally available 5 16 or 3 8 clear vinyl hose with a hose barb on one endt Locally available Footnotes 1 2 Used to provide source of known quality fuel or to bypass boat fuel system as required Should be used only by trained Marine Technicians and only for short term diagnostic purposes Used for both pressure and vacuum tests Gauge Guard is not necessary Reads from absolute zero to 199 9 PSI 3 Can be used to apply slight pressure to test fuel systems for leaks 4 Must have a minimum of 100 milliamps draw but not more than 300 milliamps 5 Contains six tools for removal of terminal pins from harness blocks 6 rj 8 9 1 Such as the Ferret 80 series from Stevens Instruments and other suppliers Such as Snap On MT14GS15SV Used to listen to fuel injectors air leaks fuel pump s and IAC operation Used to check fuel pressure regulators for leakage and to attach vacuum gauge 0 Used to check the VST vent line for the presence of raw fuel Tool Manufacturers Cole Parmer Instrument Co Rinda Technologies OTC Tools SPX Corporation Fluke Corp 800 323 4340 4563 N
55. Table of Contents Page Speed Density Theory and Operation 1 1 Speed Density Theory 1 1 Mass Air Flow Systems 1 1 Speed Density Operation 1 2 Abbreviations 1 3 MEFI ECM Input and Sensor Descriptions 1 4 PCM 555 03 Input and Sensor Description 1 5 Two Wire Sensors ECT and IAT 1 6 Three Wire Sensors MAP TP and FP 1 6 ECM555 and PCM555 03 Identification 1 8 Factors Determining Fuel Injector Pulse Width 1 9 MEFI 3 and Audio Warning 1 12 Additional MEFI 3 ECM Features 1 13 Moving Desired RPM Mode ECM s with Delphi 1623999 1 13 Load Anticipation Mode Tet Shift Switch Operation 1 13 ECM PCM 555 Engine Guardian Strategy amp Additional Guardian Sensors 14 ECM 555 Warning System Operation 1 15 Manifold Vacuum Pressure Reference Chart 1 18 Vacuum Gauge vs Map Sensor 1 19 Fuel Systems Diagrams 1 20 Multi Port Injection with Vapor Tank VST 1 20 350 Magnum Multi Port Injection with MEFI 1 and MEFI2 1 21 350 Magnum Multi Port BIET with MEFI 3 E Se 1 22 Throttle Body Injection With Vapor Separator Tank VST 1 24 Throttle Body Injection With Cool Fuel System 1 25 14i EFI SYSTEM COMPONENTS OPERATION Fuel Pressur
56. URE SENSOR SIGNAL 475 GRN MANIFOLD 416 GRY 5 VOLTS REFERENCE ABSOLUTE PRESSURE 432 LT GRN MAP SIGNAL MAP SENSOR sia BLK 814 BLK SENSOR GROUND ENGINE COOLANT a 814 TEMPERATURE ENGINE COOLANT 410 YEL TEMPERATURE ECT SENSOR SIGNAL 496 DK BLU KNOCK SENSOR 1 mm OIL PRESSURE CJ Ta sup SWITCH KNOCK SENSOR 1 r 150 BLK COE aaa 906 TAN WHT E LUBE BOTTLE 150 BLK SHIFT SWITCH SHIFT INTERRUPT 207 PPL SIGNAL 76098 MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 37 Wiring Diagram MEFI 3 with Mercury Distributor V6 and Small Block V8 3 of 4 TO FUEL PUMP RELAY FUSE 440 ORN 3 BATTERY 2 RED n ECM BAT FUSE 4400RN gt gt TODLC DLC 15A CONNECTOR IGN INJ FUSE 902 RED 439 PNK IGNITION 150 BLK TO INJECTORS AND FUEL PUMP RELAY 902 RED DISTRIBUTOR 450 BLK ECM WHT GRN E WHT RED GROUND 450 BLK ECM GROUND 450 BLK ECM GROUND ECM 439 PNK 430 PPL WHT DIST REF 902 RED 121 WHT 121 WHT IGN COIL IGNITION COIL TEMP SENDER 121 WHT Li ES 208 BRN EE LOAD ANTICIPATION 585 TAN WHT TRANSMISSION SATAN E OVERTEMP 3 PNK 29DKGRN MEE AUDIO WARNING gt i CONNECTOR HALVES CIRCUIT TO IGN ummmm PUR TAN BLU 3 AUDIO WARNING HORN TO TEMP 0000005 TAN e BLU TAN
57. WHfd 76064 MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 35 ECM Wiring Diagram MEFI 3 V6 and Small Block V8 1 of 4 INJECTORS ONE IF EFI FOUR IF MPI INJECTORS 2 3 5 8 IF FOUR From INJ ECM 481 FUSE BL 467 DK BLU INJECTOR DRIVER 10 AMP 439 PN INJECTORS ONE IF EFI FOUR IF MPI INJECTORS 1 4 6 7 IF FOUR 481 468 DK J1 17 BIMJECTOR DRIVER A 21 17 OR DRIVE From B i 439 PN 2 RED s 465 DK GRN WH J1 23 B FUEL PUMP RELAY 339 FUEL PUMP RELAY FUSE 15A FUEL PUMP RELAY FUEL PUMP 1 10 6 so 441 BRN OR BLU WHT IAC COIL A HIGH IDLE AIR im CONTROL 442 RED OR BLU BLK IAC COL A LOW IAC VALVE 443 YEL OR GRN WHT MAC COIL B HIGH 444 GRN BLK IAC COIL B LOW 461 ORN SERIAL DATA 916 YEL MASTER SLAVE 150 BLK DLC 1 CONNECTOR 450 BLK mE FROM ECM BAT 451 BLK WHT DIAGNOSTIC TEST FUSE TERMINAL 15 MALFUNCTION INDICATOR LAMP L 440 ORN 419 BRN WHT 76097 1 36 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 0804 35 Wiring Diagram MEFI 3 V6 and Small Block V8 2 of 4 TEMPERATURE IAT T 472 TAN INTAKE AIR TEMPERATURE ATURE IAT Mim IAT SENSOR SIGNAL 813 NEM SENSOR GROUND 813 BLK THROTTLE POSTION 417 DK BLU THROTTLE POSITION SENSOR TP SENSOR SIGNAL 5 VOLTS AIS GRY REFERENCE FUEL PRES SURE SENSOR FP FUEL PRESS
58. a hard start complaint The crank position sensor CPS fuel pump and injectors on ECM 555 equipped engines can be easily checked Remove the CPS from the engine With the harness attached to the CPS and with the ignition switch on rapidly pass the flat side of a screwdriver blade close to the sensor tip A scan tool will show RPM the injectors will fire and the fuel pump will run if the sensor is functioning TOOLS amp TECH TIPS 2 13 DIAGNOSTICS Table of Contents Testing Fuel System Pressure on EFI Throttle Body Injection Systems Fuel Pressure Test Gauge Adaptor Ee Testing Mechanical or Electric Fuel Supply Pump used on VST models Precautions Throttle Body Injection With Vapor Separator Tank VST Testing Fuel System Pressure on EFI Systems Testing Boost Pump If so equipped Precautions Checking for Restrictions Vapor Lock Problems in Fuel Delivery Systems Delco EST Ignition Troubleshooting Erratic Spark Symptoms No Spark Troubleshooting Non Scan Diagnosis of Driveability Concerns With No Codes Set Out of Range 3 DIAGNOSTICS Page 3 1 3 1 3 2 3 2 3 3 3 4 3 4 3 6 3 8 3 8 3 8 3 10 3 11 Scan Tool Use With Intermittents Quicksilver Digital Diagnostic Terminal Data Screen Information MEFI ECM s Data Log Sheet DDT PCM 555 03 and ECM 555 Data Log Sheet
59. act mating surfaces 4 Incomplete mating of the connector halves during initial assembly or during subsequent troubleshooting procedures 5 Tendency for connectors to come apart due to vibration and or temperature cycling 6 Terminals not fully seated in the connector body 7 Inadequate terminal crimps to the wire Wire harnesses should be replaced with proper part number harnesses When signal wires are spliced into a harness use the same gauge wire with high temperature insulation only With the low current and voltage levels found in the system it is important that the best pos sible bond be made at all wire splices by soldering the splices as shown in the following il lustrations Use care when probing a connector or replacing connector terminals It is possible to short between opposite terminals If this happens certain components can be damaged Always use jumper wires with the corresponding mating terminals between connectors for circuit checking NEVER probe through connector seals wire insulation secondary ignition wires boots nipples or covers Microscopic damage or holes will result in eventual water intrusion corrosion and or compo nent or circuit failure NOTE Warranty repairs normally require the installation of a new harness 1 Locate damaged wire 2 Remove insulation as required CUB 73048 3 Splice two wires together using splice clips and rosin core solder 73048 4 Cover splice with heat shrink sl
60. at the boots are not split at either end Remove the distributor cap and check for signs of moisture and carbon tracking A If there is no spark and the engine is equipped with Delco EST ignition unplug the 4 con nector at the distributor and recheck spark If spark is still not present the fault is isolated in the EST ignition system and is not an EFI system fault With the 4 pin connector discon nected this ignition can be diagnosed in the same manner as the 3 0 liter carbureted engine B If there is no spark and the engine is equipped with the Mercury Marine Thunderbolt distribu tor refer to Service Bulletin 99 2 for troubleshooting procedures These engines do not have a separate ignition module instead they use the MEFI 3 ECM to control the ignition coil prima ry circuit MerCruiser EFI II 1003 DIAGNOSTICS 3 21 EFI Troubleshooting Guide MEFI Systems cont Xl Check for adequate fuel pressure at the throttle body or fuel rail A If there is no fuel pressure check that the fuel pump is actually operating The pump must run for at least 2 seconds each time the key is turned to the on position If the fuel pump and the warning horn are not operating as the key is turned on make sure the ECM is powering up check the fuses and the system relay B On TBI models the fuel pressure must be constant at all speeds and must be 30 psi 2psi C OnMPI models the fuel pressure varies with engine vacuum Fuel pressure w
61. ck IMPORTANT The internal battery for the Interface Module P N 91 854013 1 MUST BE in good working condition to obtain stable tachometer readings A low battery voltage will give erratic readings PROCEDURE 1 Plug interface module into DMT2000A meter Refer to Figure 1 1 Red lead plugs into the VOHz port and the Black lead into the COM port 2 Position rotary function selector to DC Voltage V position 3 Reading should be 2 8 Volts or higher 4 Replace interface module battery if reading is below 2 8 Volts Figure 1 1 DMT2000A and Interface Module MerCruiser EFI II 1003 TOOLS amp TECH TIPS 2 7 Tachometer Secondary Inductive Pick Up IMPORTANT Use the 2STR range for tachometer testing on the Mercury Mariner 4 Stroke Outboards Refer to DMT2000A information in this User s Manual for addi tional information and instructions PROCEDURE 1 Plug interface module into 2000 meter refer to Figure 1 2 Red lead plugs into the VQHz port and the Black lead into the COM port Plug Inductive Clamp P N 91 854010 into interface module with lead marked to Red port and lead marked to Black port Position rotary function knob to IP RPM Inductive Depress RANGE button to select 2STR or ASTR See important above Clip Inductive Clamp to high tension spark plug lead Read RPM on DMT2000A Display 2 8 TOOLS amp TECH TIPS Figure 1 2 DMT2000A With Filter and
62. d density reading The programming engineer has to come up with these figures because the ECM is not actually calculating the Mass Air Flow The speed density system depends on the engine being unmodified from its original produc tion state If we change the volumetric efficiency of the engine in any manner the amount of air flow for a given rpm and air density will change causing the ECM to deliver the incorrect amount of fuel Any modification to the following components will influence the air flow through the engine throwing the speed density system out of calibration 1 Pistons and combustion chambers anything that changes the compression ratio Camshaft changes effecting the valve timing lift and duration Changes to intake and exhaust valve size as well as porting and polishing Installing different intake and or exhaust manifolds UU pe qu Installing a different size throttle body and or flame arrestor Mass Air Flow Systems Mass Air Flow systems actually measure the amount of air or Air Mass entering the engine so they generally can compensate for modifications or changes to the air flow through the engine While these systems are generally considered more accurate they are generally not as robust and cost effective as the speed density system Mass Air Flow systems are typi cally used in automotive applications to meet stringent emissions and fuel economy require ments One method of measuring the mass
63. e general warning 2 cause a continuous horn on all models However certain ECM s will sound the horn in one of two modes soft alarm 1 second 3 seconds off below 3000 rpm and a hard alarm constant horn above 3000 rpm when an Active code is detected when battery voltage is below 9v at the ECM for at least 5 seconds and when fuel pressure is too low for 5 seconds on small block models only Refer to Service Bulletin 99 3 revised 12 99 for specific serial numbers and ECM checksum numbers these additional features are being disabled in current production engines The ECM incorporates an integral ignition module coil driver circuit This is only used on the small block V6 amp V8 models except Scorpion models A standard thunderbolt distributor and ignition coil are used but the ECM controls ignition coil dwell and timing This integral module is not used on big block models ECMs with GM part 1623999 will incorporate a Moving Desired Idle mode that operates between 0 and 5 Throttle plate opening This will allow more consistent speeds at part throttle operation since the ECM will attempt to maintain a steady rpm within this range Inboard applications have a Load Anticipation Mode Additional IAC counts are added when in either gear and are removed when in Neutral A neutral safety type switch is connected to ECM J2 20 It is normally closed grounded in Neutral and is open ungrounded in either gear The MEFI 3 ECM
64. e Regulator Assembly Cool Fuel System Fuel Pressure Regulators Fuel Pressure Regulator Identification Revised Aug 6 2004 Fuel Injectors 1 Throttle Body Injection TBI Fuel Injector Multi Port Injection MPI Fuel Injector Fuel Injector Identification Revised Aug 6 2004 Engine Wiring Diagrams MEFI 3 MCM 5 0L EFI 5 7L EFI and 350 Mag MPI Engines MEFI 3 350 Magnum MPI and All Black Scorpion Engines ECM Wiring Diagram MEFI 3 V6 and Small Block V8 1 of 4 ECM Wiring Diagram MEFI 3 V6 and Small Block V8 2 of 4 ECM Wiring Diagram MEFI 3 with Mercury Distributor V6 and Small Block V8 3 of 4 ECM Wiring Diagram MEFI 3 with GM EST Distributor V6 and Small Block V8 4 of 4 PCM 555 Charging Harness 555 10 Pin Harness Circuit PCM 555 Crank Position and Camshaft Position Circuits PCM 555 Fuel Injector Harness PCM 555 Ignition Circuit PCM 555 Coil Harness Circuit Gen III Cool Fuel System MerCruiser EFI II 0804 Speed Density Theory and Operation Speed Density Theory All MerCruiser EFI engines operate on the fuel injection strategy called Speed Density This means that the ECM primarily looks at the engine s speed and the intake manifold s air densi ty in order to calc
65. e computer also changes Limiting Resistor ECM TYPICAL SENSOR 3 Wire Sensor 1 6 EFI SYSTEM COMPONENTS OPERATION VOLTAGE OUT SIGNAL INPUT MerCruiser EFI II 1003 1 Il 123 JeSinaDJelN 001 4 4 NOILIVH3dO SLN3NOdMWOO WALSAS 159 MEFI Controller J2 Center of Hole 6 yy Center of Hole 5 16 y 7 Original GM Marine ECM Housing ECM s have power reduction G M E C M MEFI amp Controller MEFI Controller J1 Center of Hole 4 Center of Hole y 13 16 New Small GM Marine ECM Housing 16210729 MODEL a WADE le Identification Delphi ECM number 16236999 have floating desired idle speed Delphi ECM number 16237009 don t have floating desired idle speed ECM 555 and PCM 555 03 Identification Identify the controllers above A B Typical ECM PCM Calibration Label 496 MAG HO a Engine Model 86361 9 6 b Calibration Part Number 859610 c Model Year MY2002pOAACS 0091 8 1 HOSDM P AB12345678 1 8 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 4 Factors Determining Fuel Injector Pulse Width NOTE The charts below are shown as examples only and represent no particular engine or ECM MAP amp RPM vs Injector on Time Base Pulse Width BPW L9 sp 7 90 s 65 75 85 w ap 8 7 Base Pulse Width Multiplie
66. e distributor frame The voltage must drop several volts as the module grounds the negative side of the coil If not replace the ignition module e When the negative battery lead is disconnected from the distributor frame the voltage must rise back to battery voltage and the ignition coil should fire If the voltage changes but the coil does not fire replace the ignition coil the secondary windings are open or shorted f When finished reconnect all leads and connectors DIAGNOSTICS 3 9 Non Scan Diagnosis of Driveability Concerns With No Codes Set If a driveability concern still exists after following the diagnostic circuit check and reviewing Troubleshooting an out of range sensor may be suspected Because of the unique design of the EFI system fail safes have been incorporated into the ECM to replace a sensed value with a default value in the case of a sensor malfunction or sensor wiring concern By allowing this to occur limited engine performance is restored until the vessel is repaired A basic un derstanding of sensor operation is necessary in order to diagnose an out of range sensor If the sensor is within its working or acceptable parameters as shown Figure A the ECM does not detect a problem If the sensor should happen to fall out of this window a code will be stored A known default value will replace the sensed value to restore engine performance If the sensor is out of range but still within the ope
67. e the filter assembly from the Cool Fuel Module at this time 7T Allow any fuel that may be in the filter assembly to drain out through the bottom of the filter assembly and into the Cool Fuel Module filter reservoir 8 Remove the filter cup from the filter cap by grasping the filter cap and rotating it in a clockwise direction while holding the filter cup stationary 9 Remove the used water separating fuel filter element from the filter cup place it in a clean approved container 3 38 DIAGNOSTICS MerCruiser EFI I 0804 Electrical 10 Dispose of any water or debris that may be in the filter cup 11 Install a new water separating fuel filter element into the filter cup Push the element into the cup until completely seated Inspect O ring in cap and replace if necessary 12 Attach the filter cap to the filter cup by grasping the filter cap and rotating it in a counter clockwise direction while holding the filter cup stationary until filter cap locks securely into place 13 Install the fuel filter assembly slowly into the Cool Fuel Module to prevent spilling fuel and align the screws retained in the filter cap with the screw holes in the Cool Fuel Module Tighten the filter assembly retaining screws until hand tight 14 Torque each filter assembly retaining screw Deck m Fiterassembiyretaningserew e amp 15 Reconnect the Cool Fuel Module harness to the engine wiring harness 16 Supply cooling
68. e unit Fuel flows through filter before getting to lift pump e More Reliable Fewer components Fewer fuel paths e Better Accessibility e Production Friendly Eliminates installation of separate pre filter at OEM Re usable consumer serviceable filter element Pull element dump water re install continue voyage MerCruiser EFI II 0804 EFI SYSTEM COMPONENTS OPERATION 1 47 This system will be standard on e Small Block MPI V8 Bravo e Small Block MPI MIE e Big Block MPI Sterndrive e Big Block MPI MIE It will not be available on e V6 Sterndrive e Small Block Ski e Small Block Alpha System Overview e Water Separating Filter Element e 2pumps Lift amp Pressure Lift pump Gerotor Pressure pump Turbine e Fuel Pressure Regulator New 288 kpa 42 psi regulator O rings seal between OD on regulator and ID in cover rather than a face seal and return hose Regulator dumps excess fuel to inlet side of pressure pump Fuel pressure vs flow characteristics differ slightly from Gen 11 requires minor calibration changes e Internal Low Pressure Relief Valve Limits pressure across lift pump to 10 psi 5 psi Dumps fuel to inlet side of filter 1 48 EFl SYSTEM COMPONENTS OPERATION MerCruiser EFI II 0804 System Module Features Dual Pump Configuration Improved Vapor Lock resistance compared to engines equipped with current boost pumps Corrosion Protection Strontium c
69. eeve to insulate from other wires 73048 MerCruiser EFI II 1003 GENERAL INFORMATION 4 13 Wiring Connector Service NOTES Most connectors in the engine compartment are protected against moisture and dirt that could create oxidation and deposits on the terminals This protection is important because of the very low voltage and current levels found in the electronic system The connectors have a lock which secures the male and female terminals together A secondary lock holds the seal and terminal into the connector When diagnosing open circuits are often difficult to locate by sight because oxidation or ter minal misalignment are hidden by the connectors Merely wiggling a connector on a sensor or in the wiring harness may locate the open circuit condition This should always be consid ered when an open circuit or failed sensor is indicated Intermittent problems may also be caused by oxidized or loose connections Before making a connector repair be certain of the type of connector Some connectors look similar but are serviced differently Replacement connectors and terminals are listed in the Parts Catalog Ensure that the connector seals are not deformed or crushed when mating the connectors together 4 14 GENERAL INFORMATION MerCruiser EFI II 1003
70. er can catch glitches as quick as a micro second 3 24 DIAGNOSTICS MerCruiser EFI II 1003 PCM ECM 555 Diagnostics continued V B Ifthe fault is an abnormal operating condition repair the system as needed For example if the sea pump pressure is low check the water pickups for obstructions then replace the water pump impeller and other parts as needed Abnormal operating condition faults can be active or intermittent C Faults rarely indicate a defective PCM ECM Assume that the is working cor rectly until complete and thorough troubleshooting procedures prove otherwise If no faults are present but you still have an observable symptom then the problem is with a component or system that the PCM ECM cannot monitor Carefully perform the Visual Physi cal check in the following section and check for obvious things such as incorrect fuel pres sure engine mechanical problems exhaust blockage etc A The problem may be that a sensor is out of calibration or it may be that the problem has nothing to do with the EFI system clogged fuel supply system mechanical engine prob lems etc B You can use the scan tool to fire the ignition coil s with or without the spark plugs installed You can also use the scan tool to drop cylinders while running to do power balance tests On PCM models each cylinder s injector can be dropped individually On ECM models each injector bank can be dropped individually
71. good battery Check the battery cable connections Make sure they are clean and tight If present discard wing nuts and replace with corrosion resistant hex nuts A corrosion resistant toothed washer should be installed between the battery terminal and the cable end stack up must be battery terminal wash er cable nut Make sure the cable connections are tight at the starter solenoid and that the block fuse on the starter solenoid if present is tight and its through bolt is not loose Also make sure the ground stud is not loose in the engine block and that its nut is tight If there is any doubt about the mechanical condition of the engine perform a compression test Make sure the safety lanyard is correctly installed and that the customer understands the correct starting procedure clear flood mode Check that all grounds are clean and tight If the negative battery cable is connected to the ground stud that does not contain all of the EFI and engine wiring harness ground leads consider moving the negative battery cable to that ground stud Check all vacuum lines for splits kinks and proper connections The fuel regulator on MPI models must be connected to manifold vacuum while the fuel regulator on TBI models cool fuel models must be vented to atmospheric pressure usually at the flame arrestor The PCV valve used on newer models is a calibrated air leak if it is missing or the incorrect valve is installed engine opera tion will be effec
72. guide 91 854015 1 Test Leads 91 802651 Optional Accessories 8 ft 2 4m inductive pick up 84 854016 T extension Clamp on Current Probe 91 802650 1 Direct Voltage Adaptor 91 89045 1 Order on MIDAS or contact Quicksilver Sales at In USA Phone 920 929 5589 Fax 800 457 8736 Quicksilver Marine Parts and Accessories Products of Mercury Marine Fond du Lac WI 54936 1939 USA MerCruiser EFI II 1003 TOOLS amp TECH TIPS 2 3 Mercury DMT 2000 FAQ S e What battery does the DMT 2000A take and where is it located A The DMM requires a 9 volt alkaline battery and is located inside the meter at the bottom of the case inside e Q The DMT 2000A keeps using up batteries A The instrument has a sleep mode and not auto power off Since you may do long term recording there is still a battery draw on the system and it will go dead This is a normal condition and must be turned off manually each time e What sizes are the fuses and what are the part numbers A There are 2 fuses The small fuse is a 2 amp MT586 2 and the large fuse is a 10 amp MT586 3 e The display starts loosing segments and has unusual figures in cold weather what could be wrong A Check your operating temperature It s common for an LCD to freeze below 32 degrees F e Q The meter reads Ouch is it broken A No On Ohms the meter will reach Ouch to signify infinite Ohms On the temperature selection it means the thermocoup
73. he circuit is Reset the circuit breaker Go to Step 7 Go to Step 7 Obtain appropriate Are you using the correct version of scan Go to OBD version of tool software for the engine in question System Chart software Go to OBD System Chart MerCruiser EFI II 1003 DIAGNOSTICS 3 29 555 On Board Diagnostic OBD System Chart Step Action Connect scan tool to the engine Ignition ON Is the scan tool communicating with the ECM Ignition ON Check for battery voltage B at Pin 5 of the 10 pin connector coming from the helm Ignition OFF With the ignition ON was present Ignition ON Check for B at ECM Connector B 18 Ignition OFF With the ignition ON was present Check for continuity between Pin 5 of the 10 pin Connector of the engine harness and ECM Connector B 18 Was continuity present 3 30 DIAGNOSTICS Yes Go to Step 2 Go to Step 10 Go to Step 4 Go to Step 6 No MerCruiser EFI II Go to Visual Physical Checklist Go to Step 3 Locate and repair problem from the keyswitch to the engine ten pin connector Re test system Go to Step 6 Go to Step 5 Locate and repair the open in the harness Re test system 1003 555 On Board Diagnostic OBD System Chart continued MerCruiser EFI Il 1003 Ignition ON Check for at Diagnostic connector Pin D Ignition OFF With the ignition ON was B present
74. here the spark goes not when it goes Rotating the distributor from its properly indexed position will cause the spark to jump to the wrong tower in the distributor cap 5 IMPORTANT On ECM555 engines when the crankshaft is EXACTLY at 1 TDC compression the distributor s rotor must EXACTLY align with the 6 V6 engines or 8 V8 engines cast into the distributor housing If not the spark will jump to the wrong tower in the distributor cap MerCruiser EFI II 1003 DIAGNOSTICS 3 27 PCM ECM 555 Diagnostics continued DTS Faults Faults relating to the ERC electronic remote control are only displayed on the System View SC5000 There are 3 potentiometers in an ERC 1 for shift control and 2 for throttle control as well as switches for trim control system view cursor control and other features Faults relating to the ETC electronic throttle control and the ESC electronic shift control are displayed on the DDT and the System View Two TPS sensors are integrated into the ETC The ETC is replaced as an assembly and is not serviceable There are 6 wires on an ETC Sensor Power Sensor Ground TP1 signal TP2 signal and 2 wires to run the servo motor The ESC contains one integrated sensor like a TPS The ESC is replaced as an assembly and is not serviceable There are 5 wires on an ESC Sensor Power Sensor Ground Sensor Signal and 2 wires to run the servo motor A separate 2 wire Neutral Switch is used to cros
75. ick Reference Chart cont 5 Guardian Strategy 6 IAC Output Lo or Hi 7 Knock Sensor 1 Hi or Lo 8 Low Drive Lube Strategy MCM engines only 9 Low Pressure Strategy 10 Main Power Relay Output 11 Main Power Relay Backfeed MerCruiser EFI II 1003 5 0 Engine block pressure map sensor oil pressure starboard exhaust temperature engine coolant temperature or overspeed readings are out of normal ranges 6 0 Cut harness wire bad harness connection short in harness 6 1 Faulty IAC pindle stuck 7 0 Corrosion or wear on the sensor 7 1 Open or short in circuit 8 0 Improper hose routing 8 1 Float in bottle stuck 8 2 Short in circuit 8 3 Incorrect gear lube level 8 4 System leak 9 0 Faulty sensor readings 9 1 Faulty oil pump 9 2 Low oil level 10 0 Short in MPR circuit 10 1 Low battery voltage 10 2 Faulty MPR 11 0 Driver power from some other source 11 1 Short in circuit at splice 105 5 0 Other fault codes will appear on the diagnostic tool Verify repairs associated with the other faults Scan for faults again 6 0 Inspect IAC wiring circuit Repair 6 1 Replace IAC 7 0 Replace sensor 7 1 Inspect harness Repair or replace harness 8 0 Route hose as shown in installation manual 8 1 Replace bottle 8 2 Inspect circuit Repair or replace harness 8 3 Fill drive lube monitor Refer to appropriate service manual for filling instructions 8 4 Inspect drive lube syste
76. ill be high dur ing cranking low at idle and increase proportionally as the throttle is opened to the wide open position Disconnect the vacuum line to find the regulator s rated pressure then reconnect the vacuum line to make sure the pressure drops at idle Pressure specifications are 30 36 or 43 psi 2psi depending on model and year Pressure usually drops about 6 psi at idle from the regulator s rated specification Refer to the service manual for specifications D If fuel pressure drops at higher speed and higher engine loads check the boat s fuel system the supply system for restrictions with an accurate vacuum gauge and clear hose at the wa ter separating fuel filter s inlet As the engine is run from idle to wide open throttle and back to idle the clear hose must not show the presence of any air bubbles and the vacuum gauge must not read higher than 2 in hg Refer to Service Bulletin 99 7 for additional information E If the supply system tests ok but the fuel pressure is low at high speeds and loads replace the water separating fuel filter and retest If pressure is still low most likely the fuel pump is defec tive XII Unplug and inspect the main harness 10 pin connector between the engine and boat harnesses If there is any doubt about the boat harness substitute a shop harness and key switch assembly and rerun the boat If the problem disappears the problem is in the boat harness not the Mer Cruiser engine harnes
77. ious bodily injury or death Careful periodic inspection of entire fuel system is mandatory particularly after storage All fuel components including fuel tanks whether plastic metal or fiberglass fuel lines fittings fuel filters and carburetors fuel injection components should be in spected for leakage softening hardening swelling or corrosion Any sign of leakage or deterioration requires replacement before further engine operation Because of possible adverse effects of alcohol in gasoline it is recommended that only alcohol free gasoline be used where possible If only fuel containing alcohol is available or if the presence of alcohol is unknown in creased inspection frequency for leaks and abnormalities is required IMPORTANT When operating a MerCruiser engine on gasoline containing alcohol storage of gasoline in the fuel tank for long periods should be avoided Long periods of storage common to boats create unique problems In cars alcohol blend fuels normally are consumed before they can absorb enough moisture to cause trouble but boats often sit idle long enough for phase separation to take place In addition internal corrosion may take place during storage if alcohol has washed protective oil films from internal components 4 2 GENERAL INFORMATION MerCruiser EFI II 1003 Fuel Delivery System Boating standards NMMA ABYC etc and Coast Guard regulations must be adhered to when constructing the engine compartment
78. lator to find the regulator s rated pressure then reconnect the vacuum line to make sure the pressure drops at idle Pressure specification is 43 psi 2 psi on all models Pressure usually drops about 6 8 psi at idle from the regulator s rated specification NOTE Remember that PCM and some ECM models use a boost pump that must maintain 7 9 psi at all speeds and loads This means that the water separating fuel filter is also pressurized at 7 9 psi All Boost pumps must use a pre filter refer to Service Bulletin 2002 02 and 2002 03 for pre filter information C If fuel pressure drops at higher speed and higher engine loads check the boat s fuel system the supply system for restrictions with an accurate vacuum gauge and clear hose at the water separating fuel filter s inlet As the engine is run from idle to wide open throttle and back to idle the clear hose must not show the presence of any air bubbles and the vacuum gauge must not read higher than 2 in hg Refer to Service Bulletin 99 7 for additional information D If the supply system tests ok but the fuel pressure is low at high speeds and loads replace the water separating fuel filter and retest If pressure is still low most likely the fuel pump is defective E All PCM ECM models use a dummy fuel pressure regulator on the fuel rail This is not used on marine applications but is a GM supplied part The vacuum line attached to the dummy regulator is a possible
79. le is not inserted or has an open circuit on the thermocouple Also when in the manual ranging mode the meter will read Ouch to indicate the range needs to be increased e The temperature reads Ouch and just replaced the thermocouple is there a field fix A Yes Since the temperature and mA range share the 2 amp fuse check for this fuse failure Also check for thermocouple continuity e What is the location of the fuses A The rubber boot should be removed and the 3 screws taken off the back cover Next split the case and remove the back cover Gently pry the circuit board out of the front case As you are looking at the circuit board selector facing you the 10 amp fuse is on the left side and the 2 amp is on the right e Can you check the fuses without taking the case apart A Yes To check the 10 amp fuse turn the selector to the temperature setting and use one test lead to bridge the common and temperature terminals The display should read close to room tempera ture To check the 2 amp fuse set the selector to the diode setting and bridge the common and Ohms terminals The display should read very close to zero Ohms if the 2 amp fuse is good e Does the DMT 2000A have Auto Power Off and Auto ranging A Yes The meter will shut off after approximately 30 minutes this is only a sleep mode there is still a power draw It is automatically in auto ranging The manual ranges can be selected using the Ra
80. m Repair or replace any worn parts 9 0 Replace sensor with a known good sensor 9 1 Replace oil pump 9 2 Check oil level add oil 10 0 Inspect MPR circuit Repair or replace harness 10 1 Charge battery or replace battery 10 2 Replace MPR 11 0 Test for voltage at 87 of the MPR with key OFF 11 1 Inspect wiring harness Repair or replace harness DIAGNOSTICS 3 33 ECM 555 System Engine Fault Quick Reference Chart cont Possible Causes 12 MAP Sensor 1 Input Hi or Lo 12 0 Loose connection corrosion 13 MAT Sensor Hi or Lo 14 Oil PSI CKT Hi or Lo 15 Overspeed 16 Pitot CKT Hi or Lo 17 seawater pump PSI Lo 18 seawater pump CKT Hi or Lo 3 34 DIAGNOSTICS open Lo or short Hi in circuit 12 1 Faulty sensor 13 0 Loose connection corrosion open Lo or short Hi in circuit 13 1 Faulty sensor 14 0 Loose connection corrosion open Lo or short Hi in circuit 14 1 Faulty sensor 15 0 Underpropped 15 1 Over trimmed condition 15 2 Rev limit out of range 16 0 Loose connection open Lo or short Hi in wiring circuit 16 1 Corroded or faulty sensor 16 2 Loose hose connection 17 0 Restricted waterflow 17 1 Faulty seawater pump 17 2 Faulty thermostat 17 3 Faulty seawater pump 17 4 Worn or broken drive belt 18 0 Loose connection corrosion open Hi or short Lo in circuit 18 1 Faulty sensor 12 0 Inspect circuit Repair or replace harness 12
81. mber the more amps it can deliver to crank the engine CCA x 1 3 2 MCA Marine Cranking Amps MCA This figure is similar to the CCA test figure except that the test is run at 32 Fahrenheit instead of 0 MCA x 77 CCA This is more in line with actual boat operating conditions Reserve Capacity This figure represents the time in minutes that a fully charged battery at 80 Fahrenheit can deliver 25 amps without dropping below 1 75 volts per cell 10 5 volts on a standard 12 volt battery The reserve capacity rating defines the length of time that a typical vehicle can be driven after the charging system fails The 25 amp figure takes into account the power required by the ignition lighting and other accessories The higher the reserve capacity rating the longer the vehicle could be driven after a charging system failure Amp Hour Rating MerCruiser EFI II 1003 The ampere hour rating method is also called the 20 hour rating method This rating repre sents the steady current flow that the battery will deliver for 20 hours while at 80 Fahrenheit without dropping below 1 75 volts per cell 10 5 volts on a standard 12 volt battery The rating is actually the steady current flow times the 20 hours Example A 60 amp hour battery will deliver 3 amps continuously for 20 hours GENERAL INFORMATION 4 7 The following battery charts list the minimum cca mca and Ah Amp hour ratings required for use on MerCruiser products
82. mps 4 7 Marine Cranking Amps 4 7 Reserve Capacity 4 7 Amp Hour 4 7 Battery Cables Length and Size 4 9 Battery 4 10 Hydrometer Tests 4 10 Capacity Tests 4 10 Charging Guide 4 11 12 Volt Battery Recommended Rate and Time for Fully Discharged Condition 4 11 Wiring Colors for MerCruiser 4 12 Wiring Harness Service 4 13 Wire 4 13 Wiring Connector Service 4 14 4 1 GENERAL INFORMATION MerCruiser EFI II 1003 Fuel Recommendations IMPORTANT Use of improper gasoline can damage your engine seriously Engine damage resulting from use of improper gasoline is considered misuse of engine and damage caused thereby will not be covered under the limited warranty FUEL RATINGS USA and Canada MerCruiser engines with the exception of the early Black Scorpions specified below in the USA and Canada will operate satisfactorily when using a major brand of unleaded gasoline having a MINIMUM pump posted Octane Rating of 87 AKI anti knock index which is the average of the RON research octane number and the MON motor octane number Federal regulations mandate that you DO NOT use leaded gasoline in the USA and Canada Higher octane fuels ca
83. n 12 5 mm Fuel Line ID 0 8 in Hg or 2 7 kPa Good See MerCruiser Service Bulletin 99 7 Rev 1 01 for information on gasoline engine vapor locking MerCruiser EFI II 1003 Delco EST Ignition Troubleshooting Erratic Spark Symptoms 1 6 If the erratic spark occurs only when the engine is warm or is especially bad on warm days remove the ignition module and make sure that plenty of thermal transfer compound is present on the module s base The module will misfire if it is too hot Verify that the purple power lead carbureted or red power lead EFI to the ignition coil is holding steady battery voltage during the erratic spark misfiring event If not check the key switch and safety lanyard switch for loose connections or internal failure a Try isolating the boat harness with a shop test harness the 3 foot MerCruiser harness part 84 812475A3 and MerCruiser ignition switch assembly part 54212A7 If the problem disappears the problem is in the boat harness not the MerCruiser engine harness b There are several splices in the purple lead on almost all MerCruiser engines so it may be necessary to go into the engine harness to find the loose connection On an EFI engine ignition coil power comes from the system relay If the purple or red power lead to the coil holds steady voltage carefully flex the pink and brown harness between the coil and the ignition module while the engine is running If the e
84. n be used on all models with the exception of early EFI models On early EFI models refer to Service Bulletin 94 12 If these engines are equipped with the original ECM 87 AKI fuel must be used and higher octane fuels must NOT be used Early Black Scorpions Black Scorpions with serial number 0L0058999 and below must use fuel with a 91 AKI minimum Black Scorpions with serial number 0L0059000 and above can use fuel with a 87 AKI minimum Outside USA and Canada MerCruiser engines with the exception of the early Black Scorpions specified below outside the USA and Canada will operate satisfactorily when using a major brand of unleaded gasoline having a MINIMUM research octane number RON of 90 The use of leaded gasoline is acceptable unless prohibited by government regulations Higher octane fuels can be used on all models with the exception of early EFI models On early EFI models refer to Service Bulletin 94 12 If these engines are equipped with the original ECM 90 RON fuel must be used and higher octane fuels must NOT be used Early Black Scorpions Black Scorpions with serial number 0L0058999 and below must use fuel with a 98 RON minimum Black Scorpions with serial number 0L0059000 and above can use fuel with a 90 RON minimum USING REFORMULATED OXYGENATED GASOLINES USA ONLY This type of gasoline is required in certain areas of the USA The two types of oxygenates used in these fuels is Alcohol Ethanol or Ether MTBE o
85. n open or short circuit or one of the leads between the sensor and the is open or shorted A CKT HI fault means that the PCM ECM is seeing a 5 0 or nearly 5 volt signal and a CKT LO fault means that the PCM ECM is seeing a 0 0 or nearly O volt signal A sensor showing a reading outside of its normal range but not shorted or open would give a fault identifying an abnormal operating condition such as ECT Coolant Overheat which means the ECT circuit is operating correctly but the engine is simply overheating Abbreviated Procedure The process begins with a Customer Complaint or when the technician notes an Observable Symptom The technician must Verify or Duplicate the complaint or symptom The technical should connect a scan tool and check for faults A If the fault is a CKT HI or CKT LO refer to the wiring diagram and check each of the leads between the suspect sensor and the PCM ECM for open and short circuits The short cir cuit does not have to be to ground it could be to any other wire in the harness If the leads test good then the sensor should be replaced 1 When troubleshooting active faults faults displayed under the Fault Status screen the circuit in question is experiencing a failure right now You are looking for an open circuit or short circuit in the 2 or 3 wires involved with the sensor in question the sen sor itself has actually failed or the connections at the PCM ECM ha
86. nes unless otherwise stated must be considered Refer to boating standards NMMA ABYC etc and Coast Guard regulations for complete guidelines 1 On Gasoline Engines Fuel tank should be mounted below carburetor level if possible or gravity feed may cause carburetor fuel inlet needle to unseat and flooding may result 2 Fuel pickup should be at least 1 in 25 mm from the bottom of fuel tank to prevent picking up impurities 3 On Gasoline Engines The maximum measured vacuum at the engine s fuel inlet must not exceed 2 in Hg or 1 psi 6 9 kPa at 600 3000 full throttle rpm and idle rpm IMPORTANT Vacuum reading higher than specified can cause vapor locking with some of today s fuels It can also cause poor engine performance because of fuel starvation 4 On Gasoline Engines Fuel lines used must be Coast Guard approved USCG Type A1 Diameter of fittings and lines must not be smaller than 5 16 in 8 mm ID on 262 CID 4 3L and 305 CID 5 0L and 350 CID 5 7L engines Diameter of fittings and lines must not be smaller than 3 8 in 10 mm 1 0 on 377 CID 6 2L 454 CID 7 4L and 502 CID 8 2L engines 5 On Multi Engine Gasoline Installations It is best to use a fuel pickup and supply line for each engine If a single pickup and line is used line must not be smaller than 1 2 in 13mm 1 0 6 Larger diameter than previously specified lines and fittings must be used on installations requiring long lines or numerous fittings
87. nge button otherwise it is always in auto ranging e While using the Inductive RPM mode on small engines the display hunts or reads higher than actual RPM or even locks up the display What can be done A Use the RPM 1 signal conditioning module e Using the RPM mode the RPM s seem to be doubled why A On some late model ignition systems with a waste spark system the plug fires twice per cycle Simply switch to 2 Stroke to obtain the correct readings 2 4 TOOLS amp TECH TIPS MerCruiser EFI II 1003 e While using the Ohms range the display is not stable A Make sure the test leads are tight in the meter Also clean the probe ends with a mild abrasive for best contact e Q With the test leads touched together the display reads 0 3 Ohms A This is the actual value of the test lead resistance To zero the display for accurate low Ohms touch the leads together and depress the Rel button to zero e the Inductive RPM function how do set the number of cylinders A It is not necessary when using this technique to measure RPM MerCruiser EFI II 1003 TOOLS amp TECH TIPS 2 5 QUICKSILVER MARINE PARTS AND ACCESSORIES 91 854009A 3 DMT2000A Digital Tachometer Multi Meter Kit po FF b Slay C 2 mum n C z CLEVER n 7 CF Hz TEMP uA 2 6 TOOLS amp TECH TIPS MerCruiser EFI II 1003 Meter Connections and Hook up Interface Module Battery Che
88. ngine runs better or quits replace the harness between the coil and ignition module This is usually because the filter in the pink lead has failed If erratic spark is still present isolate the gray carbureted or white EFI tach lead at the negative side of the ignition coil Use a suitable jumper lead to jump the purple or red lead to the ignition coil and leave the tach lead disconnected Kent Moore Jumper Lead Kit J 35616 works well or you can cut the gray or white tach lead near the ignition coil and install a bullet connector from Quicksilver connector kit part 86 813937A2 If the en gine now runs better tach lead is partially shorted to ground in the engine harness boat harness or in the tach itself Alpha EFI MEFI 1 Models if erratic spark is still present bypass shift interrupt switch with the Bravo jumper lead P N 80559241 If the engine now runs better replace the shift interrupt switch If erratic spark is still present troubleshoot the secondary system with a Kv meter No Spark Troubleshooting 3 8 DIAGNOSTICS 1 Visually check the ignition coil for melted plastic on its outer case If the case is melted the tachometer lead gray or white is shorted to ground somewhere Isolate and repair before replacing the ignition coil Make sure that battery voltage is present at the purple power lead carbureted or red power lead EFI at the ignition coil If not isolate and repair the problem in the engine
89. oated Internal water passage same as outboards External housing e coated Engine Installation Low profile water connection disconnect as required during engine installation 3 8 NPTF thread inlet fuel connection Service Access Modules located above front engine mount brackets in all applications Water Jacketed Parallel water flow through module permits smaller module Pumps immersed in fuel and draw from bottom of cavity Vapor rises to top of cavity pumps always draw liquid Reduced pump noise not audible over engine at idle No external lines between filter boost pump pressure pump and regulator Eliminates 20 external fuel connectors 5 seals not counting inlet and outlet Filter cap Modified SAE o ring seal Module Cover Controlled Crush quad ring Pressure Regulator Diametric o ring Pressure Relief Valve Diametric o ring Harness Fuel tight pass through fitting Self Draining Drains when seawater pump outlet is drained MerCruiser EFI II 0804 EFI SYSTEM COMPONENTS OPERATION 1 49 System Overview e u M HR Heat Exchanger Fuel pressure housing casting Water Outlet Low pressure 7 C g To Engine Fuel Rail Fuel Filter High Pressure Water Inlet 1st dae dui 10 psi 0 Pressure Regulato
90. on is not experiencing a failure at this time You are looking for an intermittent connection or an intermittent short circuit that is not present right now You must still check circuits for opens and shorts but you must wiggle wires and connectors during all tests in attempt to locate the poor connection Carefully look for subtle problems such as corroded connections and internal wiring harness splices and for connectors with a loose fit between the male and female pins 3 Codes rarely indicate a fault with the ECM Assume that the ECM is working correctly until complete and thorough troubleshooting procedures prove otherwise If no codes are present but you still have an observable symptom go to the diagnosis by symptom section usually called fuel injection system troubleshooting Match the observed symptom with the closest chart in the table of contents Carefully follow the troubleshooting chart to test each sus pect system or circuit The problem may be that a sensor is out of calibration or it may be that the problem has nothing to do with the EFI system If there are no codes and no observable symptoms then troubleshooting is finished 3 20 DIAGNOSTICS MerCruiser EFI II 1003 EFI Troubleshooting Guide MEFI Systems cont Visual Physical Check Il IV VI VII VIII Verify that the battery is fully charged and is of sufficient capacity for the engine being tested If necessary substitute a known
91. or from inlet side of VST tank 3 Install Fuel Pressure Connector 91 18078 to fuel supply pump or VST tank and reinstall fuel line Tighten connector and fuel line securely 4 Connect fuel pressure test gauge 0 15 psi to connector 5 Reconnect battery cables start engine and run at 1800 RPM If engine will not start crank engine to obtain reading 6 Fuel pressure should be within specifications 7 9 psi If not replace fuel pump Fuel Fitting Connector 91 18078 Description Connects fuel pressure gauge to fuel system installed between fuel supply pump and VST unit 3 2 DIAGNOSTICS MerCruiser EFI II 1003 Testing Mechanical or Electric Fuel Supply Pump used on VST models cont Throttle Body Injection With Vapor Separator Tank VST Attach Fuel Fitting Connector at Either Location 73895R1 a Fuel line from boat s fuel tank b Water separating fuel filter c Supply pump mechanical or electric d Vapor separator tank e Throttle body with 2 fuel injectors f Fuel pressure regulator g Return line to vapor separator tank MerCruiser EFI II 1003 DIAGNOSTICS 3 3 Testing Fuel System Pressure on EFI Systems 76681 a Fuel Rail Assembly b Intake Manifold c Throttle Body d Fuel Pressure Test Port Testing Boost Pump If so equipped Precautions Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion
92. r L Water Separating Fuel Filter Water Jacket High Pressure ome Lift Pump Boost Pump 1 50 EFl SYSTEM COMPONENTS OPERATION MerCruiser EFI II 0804 Fuel Flow Through the System 2 Story Water Flow Path MerCruiser EFI II 0804 EFI SYSTEM COMPONENTS OPERATION 1 51 Cool Fuel Ill System Mounted on Small Block Engine 1 52 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 Gen 11 Cool Fuel Module MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 53 TOOLS amp TECH TIPS Table of Contents MerCruiser EFI Tool List Fuel System Tools Electrical System Tools Ignition System Tools General Diagnostic Tools FOOINOUGS uen OR XR RAE Tool Manufacturers DMT 2000A Complete Kit Mercury DMT 2000A FAQ S Meter Connections and Hook up Interface Module Battery Check Tachometer Secondary Inductive Pick Up 2 i TOOLS amp TECH TIPS Direct Voltage Adaptor DVA Optional Accessory P N 91 89045 Attaching Alligator Clips Temperature Probe Clamp On Current Probe Optional Accessory P N 91 802650 P N 91 805747A2 Timing Tool for MerCruiser EFI Engines GCOBDENMATEIM sii Gienia aeiiaaie ahead Marine EFI Code Reader Rinda Scan Tools
93. r instead of a resistor type spark plug it may cause RFI that can result in the warning horn chirping or other unusual symptoms to occur DO NOT allow open spark to occur if fuel vapors might be present B A PCM can individually fire each coil An ECM only has one coil so no matter what cylinder you attempt to activate the same coil will fire in each case However the spark will attempt to go to wherever the rotor in the distributor is pointing You must test at the coil lead or know where the rotor is pointing and install the test spark plug in that cylinders lead 2 When performing the Cylinder Misfire Test the PCM ECM will add extra fuel through the fuel injectors at idle and off idle speeds but will turn off the fuel injector s at higher speeds The test is best performed under high load high speed conditions A PCM can individually control each fuel injector An ECM engine fires the fuel injectors in banks Bank 1 is 1 3 amp 5 on a V6 and 1 4 6 amp 7 on a V8 Bank 2 is 2 4 amp 6 on a V6 and 2 3 5 amp 8 on a V8 Pressing number 1 activates bank 1 while pressing number 2 activates bank 2 Pressing any other number will result in an error message 3 When firing the fuel injectors under the Auto Self Test and Output Load Test screens the same rules apply as above PMC fires individual injectors ECM fires banks 4 Timing is not adjustable on any PCM ECM engine The distributor on ECM engines only decides w
94. r ETBE If Ethanol is the oxygenate that is used in the gasoline in your area refer to Gasolines Containing Alcohol These Reformulated Gasolines are acceptable for use in your MerCruiser engine MerCruiser EFI II 1003 GENERAL INFORMATION 4 1 GASOLINES CONTAINING ALCOHOL If the gasoline in your area contains either methanol methyl alcohol or ethanol ethyl alcohol you should be aware of certain adverse effects that can occur These adverse effects are more severe with methanol In creasing the percentage of alcohol in the fuel can also worsen these adverse effects Some of these adverse effects are caused because the alcohol in the gasoline can absorb moisture from the air resulting in a separation of the water alcohol from the gasoline in the fuel tank The fuel system components on your MerCruiser engine will withstand up to 1096 alcohol content in the gasoline We do not know what percentage your boat s fuel system will withstand Contact your boat manufacturer for spe cific recommendations on the boats fuel system components fuel tanks fuel lines and fittings Be aware that gasolines containing alcohol may cause increased e Corrosion of metal parts e Deterioration of rubber or plastic parts e Fuel permeation through rubber fuel lines e Starting and operating difficulties FIRE AND EXPLOSION HAZARD Fuel leakage from any part of fuel system can be a fire and explosion hazard which can cause ser
95. r codes listed below DO NOT apply to fuel injection system harnesses ABBREVIATIONS BLACK BLK BLK All All Grounds TUB Trim Trailer Switch Protected Fused Wires from Battery RED PURPLE RED PUR Protected 12V to Trim Panel Ignition Switch 12V YELLOW RED YEL RED M Switch to Starter Solenoid to Neutral Start TAN BLUE TAN BLU Audio Warning System Also Electric Chokes on models so equipped NOTE Yellow used as GROUND wire in Europe and by some North American builders NOTES 4 12 GENERAL INFORMATION MerCruiser EFI II 1003 Wiring Harness Service Wire Repair Marine engine control circuits contain many special design features not found in standard land vehicle wiring Environmental protection is used extensively to protect electrical contacts and proper splicing methods must be used The proper operation of low amperage input output circuits depends upon good continuity be tween circuit connectors Before component replacement and or during normal troubleshoot ing procedures visually inspect any questionable mating connector Mating surfaces should be properly formed clean and likely to make proper contact Some typical causes of connec tor problems are listed below 1 Improperly formed contacts and or connector housing 2 Damaged contacts or housing due to improper engagement 3 Corrosion sealer or other contaminants on the cont
96. rCruiser 320 EFI style intake plenum Keihin injectors Black Scorpion White Tip 30 207 805225 1 Keihin 5 7L amp 6 2L V8 8 1L PCM 555 MPI Cool Fuel GM intake plenum injectors V8 496 Mag Black Tip 43 296 881693 GM Delphi 8 15 Models Neutral Tip 43 296 881693 GM Delphi e MEFI 1 22 3 ECM Engine Injector Identification Engine Color System Injector Model Code psi kPa P N Manufacture Comments V8 5 7L MEFI 1 TBI VST Non Gen 350 Mag EFI Blue Black 12 82 None GM See SB 94 8 Ski V6 4 3L V8 5 0L 5 7L MEFI 1 TBI VST and Cool Fuel Non Gen and Gen engines All V6 EFI all Pink Purple 30 207 852956 GM V8 EFI models V8 5 7L MEFI 1 MPI VST Non Gen 350 Mag MPI Orange Tip 43 296 806807 1 Keihin Bravo Ski V8 5 7L MEFI 1 MPI VST Gen 350 Mag MPI Orange Tip 43 296 806807 1 Keihin Bravo V8 5 7L MEFI 1 MPI Cool Fuel on Starboard side Gen Black Scorpion Orange Tip 43 296 806807 1 Keihin Ski 5 7L V8 5 7L 6 2L MEFI 1 3 MPI Cool Fuel on Port side Gen 350 Mag MPI White Tip 30 207 805225 1 Keihin Bravo Inbrd Ski Black Scorpion Ski 5 7L amp 6 2L 377 Scorpion Bravo amp Ski 1 32 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 0804 e MEFI 1 22 3 ECM Engine Injector Identification Contd Engine Color System Injector Model Code psi kPa P N Manufacture Comments V8 5 7L 6 2L MEFI 2
97. rating window of the ECM the problem will go undetected by the ECM and may result in a poor driveability condition A good example of this would be if the coolant ECT sensor was reading incorrectly and indi cating to the ECM that coolant temperature was at 20 F but actual coolant temperature was 175 F Figure B This would cause the ECM to believe that the engine was running cold The ECM would then control the fuel injectors to deliver more fuel than was actually needed and result in an overly rich rough running condition This condition would not have caused a code to set as the ECM interprets this as within its range LOW Temperature 5 Volts Default Range Default Range lt 20 deg F Incorrect reading sent by an Out Of Range Acceptable sensor Sensor Operating Range 175 deg F This is the actual coolant reading that should have been sent the sensor Default Range Default Range HIGH Temperature 0 Volts Figure Figure B To identify a sensor which is out of range unplug it while running the engine After approxi mately two minutes the diagnostic code for that sensor will set a code and replace the sensed value with a default value If at that point a noticeable performance increase is ob served the diagnostic testing code chart for that particular sensor should be followed to cor rect the problem NOTE Be sure to clear each code after disconnecting and reconnecting each sensor Failure to do
98. re Connection Battery 1 Oil Pressure Sender 2 Trim Sender a Positive Power Wire To EFI System Harness b Harness Connector To EFI System Harness c Auxiliary Tachometer Lead 1 34 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 33 MEFI 3 350 Magnum MPI and All Black Scorpion Engines NOTE All BLACK wires with a ground symbol are interconnected within the EFI system harness NOTE Component position and orientation shown is arranged for visual clarity and ease of circuit identification 1 Fuel Pump 13 Fuse 15 Amp Fuel Pump 2 Distributor Fuse 15 Amp ECM DLC Battery Fuse 10 5 Coil Amp ECM Injector Ignition Knock Module 4 Knock Sensor KS Module 14 Harness Connector To Starting Charging 5 Data Link Connector DLC Harness MEN 6 Manifold Absolute Pressure MAP Sensor 19 Power Wire To Engine Circuit 7T Idle Air Control IAC 8 Throttle Position TP Sensor 9 Engine Coolant Temperature ECT Sensor 10 Electronic Control Module ECM 11 Fuel Pump Relay 12 Ignition System Relay 16 Shift Plate Not used on Ski models 17 Oil Pressure Audio Warning System 18 Gear Lube Bottle Not used on Ski models 19 Fuel Pressure Switch 20 Water Temperature Sender BLK BLACK BLU BLUE BRN BROWN GRY GRAY GRN GREEN ORN ORANGE PNK PINK PUR PURPLE RED RED TAN TAN WHT YEL DRK AHM
99. require a digital voltmeter with a rating of 10 megohms input impedance DIAGNOSTICS 3 17 12 When a test light is specified a low power test light must be used NOT use a high wattage test light While a particular brand of test light is not suggested a simple test as shown below on any test light will ensure it to be safe for system circuit testing Connect an accurate ammeter such as the high impedance digital multimeter in series with the test light being tested and power the test light ammeter circuit with the vehicle battery a Test Light b Battery IMPORTANT If the ammeter indicates LESS than 3 10 amp current flow 3 A or 300 mA the test light is SAFE to use If the ammeter indicates MORE than 3 10 amp current flow 3 A or 300 mA the test light is NOT SAFE to use NOTE Using a test light with 100 mA or less rating may show a faint glow when test actually states no light 13 When using a DVOM to perform voltage measurements turn the ignition OFF when con necting the DVOM to the circuitry to be tested 3 18 DIAGNOSTICS MerCruiser EFI II 1003 Intermittent Faults IMPORTANT Problem may or may not turn the Malfunction Indicator Lamp MIL or store a DTC DO NOT use the Diagnostic Trouble Code DTC tables for intermittent problems The fault must be present to locate the problem Most intermittent problems are caused by faulty electrical connections or wiring Perform caref
100. riod V The process begins with a Customer Complaint or when the technician notes an Observable Symptom The technician must Verify or Duplicate the complaint or symptom The technical must perform the OBD On Board Diagnostic check which consists of three major steps A Verify scan tool link up communication with ECM or code 12 on the winky blinky If not go to the appropriate chart in the service manual usually Chart A 1 and or A 2 B Verify that the engine will start If not go to the no start chart usually Chart A 3 Note that the engine does not have to run correctly it just must run C Check for Diagnostic Trouble Codes If codes are present fix active codes first lowest number code to highest number code then repair logged codes in same manner Locate the code in the table of contents of the appropriate service manual and section The section is usually called general system diagnostics or just diagnostics 1 When troubleshooting active codes the circuit in question is experiencing a failure right now You are looking for an open circuit or short circuit in the 2 or 3 wires involved with the sensor in question the sensor itself has actually failed or the connections at the ECM have failed In one fashion or another the troubleshooting chart will have you check each wire for continuity and shorts and test the sensor for correct operation 2 When troubleshooting logged codes the circuit in questi
101. rness and key switch assembly and rerun the boat If the problem disappears the problem is in the boat har ness not the MerCruiser engine harness A suitable test harness can be assembled from the following components MerCruiser 3 foot instrument harness cable part number 84 812475A3 B MerCruiser ignition switch assembly part number 54212A7 C Use suitable machine screws and nuts to join the switch ring terminals to the harness s D gt ring terminals then cover the connections with heat shrink tubing A standard piezo warning horn such as 81649246 can also be added to provide audible warning of cooling system overheat low crankcase oil pressure and low drive oil level or high transmission temperature MerCruiser EFI II 1003 DIAGNOSTICS 3 25 PCM ECM 555 Diagnostics continued VII Check for adequate fuel pressure at the fuel rail A If there is no fuel pressure check that the fuel pump s is are actually operating The pump s must run for at least 2 seconds each time the key is turned to the on position If the fuel pump s and the warning horn are not operating as the key is turned on make sure the PCM ECM is powering up check the fuses and the wake up line B On PCM ECM models fuel pressure varies with engine vacuum Fuel pressure will be high during cranking low at idle and increase proportionally as the throttle is opened to the wide open position Disconnect the vacuum line on the cool fuel regu
102. rs Water Temp Deg F 0 25 s 20 10 15 18 10 Throttle Multiplier 35 15 so 20 36 30 Air Temp Deg F 0 10 1 05 30 7 00 189 109 _ MerCruiser EFI II 1003 EFI SYSTEM COMPONENTS OPERATION 1 9 I 123 JOSINIDION NOILVH3dO S LN3NOdINOO WALSAS 133 01 1 001 GM EFI ECM COMPARISON and Code Listing 1 93 95 models MEFI 1 96 98 models MEFI 2 98 350 Mag amp 129 MEFI 3 99 amp newer models GM 93 software GM 93 MEFI 1 software in a GM 96 software in a MEFI 2 case GM 98 or 99 software MEFI 2 case GM part 16210729 Largest ECM 93 95 Medium size ECM 96 98 Medium size ECM Smallest ECM square 4 short mounting bolts 4 long mounting bolts 4 long mounting bolts 3 short mounting bolts J1 J2 on opposing ends of case J1 J2 on opposing ends of case J1 J2 on opposing ends of case J1 J2 parallel to each other Same pin locations as MEFI 2 Same pin locations as MEFI 2 Same pin locations as MEFI 1 Unique pin assignments Power reduction mode active Power reduction is NOT active Power reduction is NOT active Power reduction is not active Must manually advance throttle Must manually advance throttle ECM automatically sets rpm ECM automatically sets rpm prior to base timing service mode prior to base timing service mode during base timing service mode during base timing service mode Delco EST Ignition Delco EST Ignition Delco EST Ignition EST
103. rt Hi in circuit 23 1 Faulty sensor 24 0 Short to ground in the 5 volt system harness or 3 wire sensor 19 0 Inspect circuit Repair or replace harness 19 1 Replace sensor 20 0 Inspect circuit Repair or replace harness 20 1 Replace sensor 21 0 Inspect sensor for damage Replace TPS 21 1 Inspect harness for short to ground Repair or replace harness 21 2 Inspect throttle lever Repair any damage 22 0 Inspect circuit Repair or replace harness 22 1 Inspect circuit Repair or replace harness 23 0 Inspect circuit repair or replace harness 23 1 Replace sensor 24 0 Read other faults for a starting point for finding the short Repair or replace harness or faulty sensor DIAGNOSTICS 3 35 NOTE This is a preliminary copy and it is subject to change Gen 111 Cool Fuel Module Diagnostics Models Affected SerialNumber Situation A new generation of the MerCruiser fuel cooling system has been developed and released into production The Generation Ill Cool Fuel system incorporates many design elements The following information is provided for maintenance and troubleshooting of the Generation 111 Cool Fuel Module Upon completion of these tests if problem exists replace the complete Cool Fuel Module assembly Changing Water Separating Fuel Filter Element Avoid Fire or Explosion The fuel injection system is pressurized during operation Use care when removing the water
104. s A suitable test harness can be assembled from the following compo nents A MerCruiser 3 foot instrument harness cable part number 84 812475A3 MerCruiser ignition switch assembly part number 54212A7 Use suitable machine screws and nuts to join the switch s ring terminals to the harness s ring terminals then cover the connections with heat shrink tubing A standard piezo warning horn can also be added to provide audible warning of cooling sys tem overheat low crankcase oil pressure and low drive oil level or high transmission temper ature B C D 3 22 DIAGNOSTICS MerCruiser EFI II 1003 EFI Troubleshooting Guide MEFI Systems cont Clearing Codes Codes are automatically erased after the engine has gone through its preprogrammed number of power ups l Scan tools A The Quicksilver DDT requires that the engine be running in order to clear the codes If you at tempt to clear the codes with the engine not running the scan tool will attempt to clear the codes but fail to actually accomplish it B The Rinda MerCruiser Scan tool can clear the codes with the engine running or with the engine in the key on engine off KOEO mode Il Codemate winky blinky A Clearing codes with the winky blinky requires 2 separate procedures depending on whether you are working on a MEFI 1 system or a MEFI 2 or 3 system 1 MEFI 1 It is very difficult to clear codes on a MEFI 1 system because the engine must
105. s check the integrated sensor The switch is located on the shift bracket Bravo models and is the Transmission s Neutral Safety switch on Inboard models DTS engines use a different PCM555 controller with a Motorola Base Part Number of 859611 Wiring diagrams are not in print at this time Refer to the PCM ECM spreadsheet showing the location function and color code of each PCM ECM pin 3 28 DIAGNOSTICS MerCruiser EFI II 1003 555 Troubleshooting Preliminary Checks Several of the diagnostic procedures call for the completion of a Visual Physical Checklist The importance of this step cannot be stressed too strongly It can lead to correcting a problem without further checks and can save valuable time This check is outlined below Visual Physical Checklist Yes Recharge or replace battery Is the battery fully charged Go to Step 2 E Restart d checklist Clean or tighten battery Are the battery cable connections clean Go to Step 3 cable and tight connections Go to Step 3 Clean or Are the external engine grounds tight and tighten engine Siero Go to Step 4 grounds Go to Step 4 Check fuel line and fuel line connections for Repair leaks corrosion and blockage problem Go to Step 5 Was a problem found Go to Step 5 Check the 3 fuses located next to the ECM on the engine Are the fuses good Replace fuse Go to Step 6 Check the 50 amp circuit breaker located on the engine to ensure that t
106. separating fuel filter Fuel could spray on the hot engine causing fire or explosion Allow the engine to cool down before attempting to remove the water separating fuel filter in the following procedure Be careful when changing the water separating fuel filter Gasoline is extremely flammable and highly explosive under certain conditions Ensure the ignition key is OFF Do not smoke or allow spark or open flame in the area when changing the fuel filter Wipe up any spilled fuel immediately MerCruiser EFI Il 0804 DIAGNOSTICS 3 37 Ensure that no fuel leaks exist before closing the engine hatch 1 Allow the engine to cool down NOTE Mercury MerCruiser recommends that the engine be shut off for 12 hours prior to filter removal 2 Disconnect the Cool Fuel Module harness from the engine wiring harness 3 Turn the key switch to the start position and allow the starter to operate for 5 seconds to relieve fuel system pressure 4 Turn key switch to off position 5 Loosen each filter assembly retaining screw until the screw is disengaged from the Cool Fuel Module Do not remove the filter assembly retaining screws from the filter cap 5658 a Cool Fuel Module e Fuel filter element b Cool Fuel Module harness f Filter cap c Filter cap and O ring g Cool Fuel Module filter reservoir d Filter assembly retaining screw 6 Unseat filter assembly by grasping filter assembly handle and pulling upward Do not remov
107. solenoid small yellow red terminal DO NOT attach the remote starter switch to both large terminals of the slave sole noid If this is done pressing the switch will bypass the slave solenoid and all start ing current will flow through the switch and its attaching wires This can cause equipment damage and personal injury A CAUTION 3 1003 When it is necessary to probe circuits NEVER puncture wiring insulation as this can per mit moisture to enter and result in circuit failure due to corrosion Care should also be exer cised when probing terminals in harness blocks Insertion of a probe that is too large can spread the terminal preventing good pin to pin contact when the harness block is recon nected Use of the GM style test leads PN J 35616 A and or the Rinda EFI test lead set PN 94025 can prevent both these problems When an engine won t start or starts but runs poorly be sure to not forget to check for water in the fuel and for old deteriorated fuel If either of these conditions is suspected use of a portable outboard tank can be very helpful The PG Permanent magnet Gear reduction starters used on all current sterndrive en gines are highly efficient Because of this a battery that is too weak to provide sufficient voltage at the ECM PCM to start an engine can at times turn it over so fast that the battery is not immediately suspected Don t forget to check battery voltage when troubleshooting
108. stem Fuel Pump Mechanical or Electric depending on Fuel System V Water Separating Fuel Filter Fuel Tank There is a MerCruiser specification for allowable vacuum when measured at the inlet side of the engine mounted MerCruiser Water Separating Fuel Filter or if there is none mounted on the engine at the inlet side of a fuel pump Use a digital vacuum gauge an analog gauge may not give accurate enough readings at these low levels that reads in either in Hg inches of mercury or kPa kilopascals The specification is 2 in Hg 7 kPa maximum at idle 3000 rpm full throttle and then back at idle rpm check at each point Any anti siphon valve or restriction that causes a higher reading can contribute to vapor lock ing and other driveability problems In hot weather if you see 0 vacuum on the gauge and the engine is still running poorly check the inlet fuel line to ensure that a good solid flow of fuel is in the line instead of a mixture of fuel and vapors If the vacuum is too high try a less restric tive anti siphon valve Restrictive anti siphon valves can cause vapor locking conditions Going to the next larger Inside Diameter fuel lines and fittings can help lower the vacuum also This larger diameter ID can also help correct vapor locking conditions An example is shown below 5 16 in 8 mm Fuel Line ID 5 5 in Hg or 17 8 kPa Too high 3 8 in 9 5 mm Fuel Line ID 2 5 in Hg or 8 2 kPa Too high 1 2 i
109. t the RPM range and record the pressure and vacuum readings 2 f fuel supply vacuum reading is greater than 2 Hg find and correct fuel supply restriction 3 Iffuel supply vacuumis within specification and fuel pressure is less than 40 psi replace Cool Fuel Module 3 40 DIAGNOSTICS Use a tee fitting and connect a vacuum gauge to the fuel inlet side of the Cool Fuel Module Do not remove fuel inlet fitting adapter Cycle key switch 2 3 times OFF to RUN position at 3 second intervals to reach maximum pressure Verify that the vacuum from the fuel source is within specification If vacuum is exceeds 2 Hg excessive fuel restriction exists Correct fuel restriction before proceeding With vessel secured to the dock and engine running in neutral restrict fuel supply and verify that the Cool Fuel Module has the ability to cause a vacuum reading of 11 Hg or greater If vacuum reading is less than 11 Hg with fuel supply restricted replace Cool Fuel Module IMPORTANT It will be necessary to sea trial the boat following repairs to be sure that the pressure and fuel system vacuum remain within specification throughout the RPM range MerCruiser EFI II 0804 GENERAL INFORMATION Table of Contents Page Fuel Recommendations 4 1 Fuel Delivery System 4 3 Battery Requirements for MerCruiser ProdU6lS Liens cesa 4 7 Battery Ratings 4 7 Cold Cranking A
110. ted Check for any other additional air leaks in the induction system such as throttle body and intake manifold gaskets If the normal IAC counts for the engine are known then any air leak will result in a lower IAC count than normal Unplug and inspect the ECM J 1 and J 2 connectors Make sure there are no ECM pins bent over and that all of the correct pins are present Refer to the service manual charts for the pins used and not used Look for signs of tampering corrosion damage to the pin locking mechanisms melted insulation and any other evidence of shorts or other damage Unplug and inspect as many of the sensors and actuators as you can reasonably access Look for signs of tampering corrosion damage to the pin locking mechanisms melted insulation and any other evidence of shorts or other damage Based on the results of this inspection further inspec tion of the harness may be necessary Remember that there are many internal splices in the har ness that may be damaged or defective If there is damage on the external connections you will have to inspect several of the internal splices to verify that the damage is not also present at these locations Check for adequate secondary spark If an air gap tester is used make sure it will not ignite any fuel vapors that may be present in the bilge A KV meter can also be used to check for adequate secondary voltage Make sure the secondary wires are in good physical shape correctly routed and th
111. the boat is out of the water follow instructions for running engine on flush device as found in service manual for the engine being fogged 3 a Cool Fuel models Start and run engine at 1300 rpm for 5 minutes b VST models Start and run engine at 1300 rpm for 10 minutes 4 After specified running time is complete slowly return throttle to idle rpm and shut engine off IMPORTANT Do not run engine s fuel system dry of this fogging mixture in the 6 US gal 23 L remote outboard fuel tank Page 2 of 2 SEPTEMBER 2001 2001 15 4 6 GENERAL INFORMATION MerCruiser EFI II 1003 Battery Requirements for MerCruiser Products Battery Ratings There are two major rating systems used in the USA for marine engine cranking batteries The most common is cca cold cranking amps which rates the cranking amps at 0 F The second system mca marine cranking amps rates the cranking amps at 32 F The mca marine cranking amps rating of a given battery is always higher than the cca cold cranking amps rating There is a third rating system that some discount stores use which rates the cranking amps of a battery at 80 F The advertised cranking amps of these batteries is high while the actual cca of it is very low Cold Cranking Amps CCA This figure represents in amps the current flow the battery can deliver for 30 seconds at 0 Fahrenheit without dropping below 1 2 volts per cell 7 2 volts on a standard 12 volt battery The higher the nu
112. the fuel injector driver wire is shorted to ground the scan tool will read Open Sensor this means that the fuel injector is full Open When the fuel injector is shorted the scan tool will read Short Injector A shorted 12 volt fuel injector power lead will blow the injector fuse E F the scan tool will read Bad Fuel Pump Fuse Wire Colors on Fuel PCM Pinout Injector Harness 77696 BLK C 6 GRN BLK C 11 PNKIBLK MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 43 PCM 555 Ignition Circuit COILS 2 CAM CB d n IBZ pg AE fe T EIE az T v a Pp Ip W pm IS SPLICE SPLICE E 105 101 SPLICE 100 A SPLICE 106 B 23 5 6 14 45 6 Wto 17 42 43 1 2 Mlle 20 a a SPLICE 106 SPLICE e ho S N NE N PNY D wc BLK BLK K WHT PPL m SPLICE gt A ea E SPLICE 101 z u 105 T cre 88 gt gt a WHT BLK H B COILS 1 d 20 With initial key ON 12 volt power is sent from the battery through the purple lead in the 10 pin harness to the pink lead at Engine Harness Pin C This is wake up power to the PCM The PC
113. tion 1 14 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 1003 15 555 Warning System Operation The engine warning system incorporates an audio alarm and if installed Smartcraft Gauges System When the key switch is turned to the ON position the audio alarm will momentarily activate to test the warning system The alarm should sound once if the system is operable This table is a guick guide showing what warning output will accompany a fault Smartcraft Audio Available Constant 6 100 Engine guardian overheat condition 2 Bp min 100 Coil harness wire open 2 Bp min 100 Coil harness wire short 2 Bp min 100 Fuel injector wire open ECT CKT HI ECT CKT LO ECT Coolant Overheat EST 1 Open 1 EST 1 Short Fuel Injector 1 7 4 6 Open Guardian Strategy IAC Output LO HI 2 Knock Sensor 1 Lo Low Drive Lube Constant 100 Low oil in sterndrive Strategy LOW Y Constant 0 100 Low oil pressure strategy Strategy NOTE If any 5v sensor becomes shorted to ground the engine will not start If the engine is operating when the short occurs the engine may stop operating and will not start NOTE GM EFI ignition system failure open or shorted driver will flag EST 1 fault NOTE TPS must see 5 throttle then back to 0 to flag IAC fault NOTE 3 2 wire sensor open will read sensor Hi on scan tool NOTE 4 VDC PWR Low if shorted or no voltage engine will not start if
114. uiser EFI II 0804 350 Magnum Multi Port Injection with MEFI 1 MEFI 2 350 Mag MPI Shown Scorpion Is Similar a Vacuum Line To Intake Manifold Base b Fuel Pressure Regulator c Fuel Cooler d Electric Fuel Pump e Water Separating Fuel Filter f Fuel From Tank g Direction Of Water Flow h Fuel Line To Fuel Rail i Excess Fuel Return To Water Separating Fuel Filter j Fuel Injectors 8 k Fuel Rail MerCruiser EFI II 0804 EFI SYSTEM COMPONENTS OPERATION 1 21 1 350 Magnum Multi Port Injection with MEFI 3 350 Shown Scorpion Is Similar a Vacuum Line To Intake Manifold Base b Fuel Pressure Regulator Fuel Cooler Electric Fuel Pump Water Separating Fuel Filter Fuel From Tank Direction Of Water Flow Fuel Line To Fuel Rail i Excess Fuel Return To Water Separating Fuel Filter j Fuel Injectors 8 k Fuel Rail 0 JQ 1 22 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI II 0804 Throttle Body Injection With Vapor Separator Tank VST 73895R1 a Fuel line from boat s fuel tank b Water separating fuel filter c Supply pump mechanical or electric d Vapor separator tank e Throttle body with 2 fuel injectors f Fuel pressure regulator g Return line to vapor separator tank 1 24 EFI SYSTEM COMPONENTS OPERATION MerCruiser EFI Il 0804 24 Throttle Body Injection With Cool Fuel System 74871R1 a
115. ul visual physical check Check for the following conditions e Poor mating of the connector halves or a terminal not fully seated in the connector body backed out or loose e Improperly formed or damaged terminals and or connectors All connector terminals in the problem circuit should be carefully checked for proper contact tension e Poor terminal to wire connection crimping This requires removing the terminal from the connector body to check Refer to Wiring Harness Service in the Description and Sys tem Operation section The vessel may be driven with a Digital Multimeter connected to a suspected circuit An abnormal voltage when malfunction occurs is a good indication that there is a fault in the cir cuit being monitored A scan tool see Special Tools for part numbers can be used to help detect intermittent conditions The scan tools have several features that can be used to locate an intermittent condition The following features can be used in finding an intermittent fault The Record feature or choosing not to erase data can be triggered to capture and store engine parameters within the scan tool when the malfunction occurs This stored information can then be reviewed by the service technician to see what caused the malfunction To check loss of DTC memory disconnect TP sensor and idle engine until the MIL comes ON A trouble code should be stored and kept in memory when ignition is turned OFF If not
116. ulate the correct amount of fuel to inject The engine requires an air fuel mixture of approximately 14 7 to 1 in the combustion cham bers Since the EFI system doesn t control air flow it must determine how much air is flowing through the engine in order to calculate the correct amount of time to fire the fuel injectors The net result is that there must be 1 part of fuel for every 14 7 parts of air going through the engine Since the engine is basically an air pump we know that an engine is capable of pumping a certain maximum amount of air at any specific rpm The actual amount of air it pumps at a specific rpm depends on the density of the air in the intake manifold The air density in the intake manifold will vary depending on rpm throttle plate position and barometric pressure If the air density in the intake manifold is known the actual amount of air flowing through the engine the Air Mass or Mass Air Flow could be calculated This calculated and the actu al air flow is a repeatable function meaning that at a specific rpm and a specific manifold absolute pressure reading the air flow through the engine will always be the same However in the speed density system we do not actually calculate the actual air flow Instead the ECM measures the rpm and the air density then refers to a programmed lookup table in the ECM s EEPROM This lookup table will be programmed with the correct fuel injector information for every rpm an
117. umper plug jumps A amp B at DLC Continuity light 1 5v self powered Timing light MerCruiser EFI II 0804 91 881833A2 91 803135 8 4814 8 4914 8 4614 91 806901 91 18078 91 805918A2 J 34730A2 OTC 7188 J 34730 400 OTC 7187 J37088 A J 41769 OTC 7660 J 37088 1A or J 41769 1 J 41769 2 See current MPP Acessories Guide for selection of tanks Model No 68920 10 S 34 J 39383A OTC 7670 PV 350 Fluke 91 892647A01 91 802650 91 89045 1 J 34142 B OTC 3053S Rinda 94025 J 35616 A J 38125 B 86 813937A2 91 808696 91 881814A1 TT 600 91 52024A1 MT2700 DIS KV 91 63998A1 91 850439T1 91 805747 2 21008 Locally available TOOLS amp TECH TIPS 2 1 General Diagnostic Tools Hand vacuum pump Mity Vac or equivalent J 23738 A OTC 7059 Rinda CodeMate winky blinky 94008 Rinda MerCruiser scan tool current software version 4 0 94050m Software update for scan tool version 4 0 94056 ECM PCM 555 adapter cable 64006 Update for scan tool software and cable 94056 Rinda Diacom PC software and cable Windows Version 94010m Quicksilver DDT digital diagnostic terminal 91 823686A2 MerCruiser DDT cartridge current software version 2 0 91 803999 SmartCraft DDT cartridge version 1 3 91 880118 003 MerCruiser DDT adaptor cable DLC and injector connectors 84 822560A2 SmartCraft MerCruiser DDT adaptor cable ECM PCM 555 ECM s 84 822560A13 or 84 822560A5 and 84 822560T12
118. ury MerCruiser electronic EFI harness and the 10 pin engine harness It supplies the PCM with the analog coolant tachometer audio warning alarm and neutral safety signals A malfunction of the 10 pin harness connection will not set a fault MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 41 PCM 555 Crank Position and Camshaft Position Circuits C B A CD 8 6 6 2 Cb 3 9 6 9 0 CD 3 9 6 9 6 7 8 9 0 19 9103113132313 14 15 16 9 10 11 12 13014 15 16 12 13 14 15 16 17 18 19 20 21 17 18 19 20 21 022 23 24 17 18 19 20 21 2 24 22 23 24 25 26 27 28 29 30 G1 32 BLK PNK GRY TAN PPL WHT SPLICE 100 sPucE 101 eo 7511 za gt t 2 rel gt a x cy m z ABC A 5 CAM CRANK 8 POS POS 77680 a Crankshaft Position Sensor b Camshaft Position Sensor c 5 Volt Power d 5 Volt Ground e Signal To The PCM The crankshaft position sensor located at the rear of the engine and the camshaft position sensor located at the front of the engine supply the PCM with timing and rpm information If a failure occurs in these sensor circuits the engine will operate extremely rough or stop operating Check for continuity between the PCM and the sensor The normal resistance values for these sensors at 21 degrees C 70 degrees F are e Camshaft Position Sensor A to B 24 04 mohms and B to
119. ve failed When troubleshooting intermittent faults faults displayed under the Fault History screens or faults that are NOT active in the Fault Status screen the circuit in question is not experiencing a failure at this time You are looking for an intermittent connection or an intermittent short circuit that is not present right now You must still check circuits for opens and shorts but you must wiggle wires and connectors during all tests in attempt to locate the poor connection Carefully look for subtle problems such as corroded connections and internal wiring harness splices and for connectors with a loose fit between the male and female pins a An excellent way to find an intermittent problem is to use the data monitor function of the scan tool While observing the data from the suspect circuit wiggle the wires and connectors of the suspect circuit while the key is on or while the engine is run ning When you locate the bad connection or broken shorted lead the data reading will fluctuate on the scan tool Keep in mind that the refresh rate of the scan tool is relatively slow every 50 milliseconds or so b The record or min max function of the DMT 2000 or equivalent multimeter can also be used to monitor and record the voltage signals on the suspect circuit Use the Rinda 94025 Jumper Lead Set or equivalent to connect the meter to the suspect sensor s signal lead Sensor signals must never be 0 0 or 5 0 volts A multimet
120. vo Pink 30 207 807952 1 Regulator on fuel cooler No ring on hose 7 4L EFI Inbrd fitting V8 7 4L 8 2L MEFI 1 MPI VST MerCruiser MPI intake Keihin injectors All 7 4L amp 8 2L Unknown 36 248 805227 1 Regulator on fuel rail Hose fitting points toward MPI models port side V8 7 4L 8 2L MEFI 1 MPI Cool Fuel MerCruiser MPI intake Keihin injectors All 7 4L amp 8 2L Yellow 36 248 860349A 1 Regulator on fuel cooler Black ring on hose MPI models Orange fitting Regulator on fuel rail does not control fuel pressure V8 7 4L 8 2L MEFI 3 MPI Cool Fuel MerCruiser MPI intake Magneti Marelli injectors All 7 4L amp 8 2L Blue 43 296 861126A 1 Regulator on fuel cooler Green ring on hose All 7 4L amp 8 2L fitting No regulator on the fuel rail V8 8 2L MEFI 3 MPI Cool Fuel MerCruiser MPI intake HP500 EFI Blue 43 296 861126 1 1999 UP Green ring on hose fitting Brown V8 8 2L MEFI 3 Dual TBI Cool Fuel Super Charger intake GM TBU HP575 SCi Pink 30 207 807952 1 2000 UP No ring on hose fitting MerCruiser EFI Il 0804 EFI SYSTEM COMPONENTS OPERATION 1 29 Fuel Injectors The EFI injector assembly is a solenoid operated device controlled by the ECM that meters pressurized fuel to engine cylinders The ECM grounds the injector solenoid which opens a valve allowing fuel to flow past the valve The injector tip has holes that control the fuel flow generating a conical spray

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