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1. Sheet 12 of 14 Jul 30 1996 U S Patent 53080534 1 0 SALV IdW31 S31V 19 31 TOHLNOD 03345 531771931 H3H10 31V IidW3l 31V IdW3l 31V 19 31 AINVHI SIN3A3 11880 WOUJ 5 19510 139 5341197353 WIIsdS 439090934 1 0 S31V ldW31 N33u9S NOILVWHOJNI 3 JIH3A N33H9S NOILVWHOJNI 21150 9 0 3151 3 521150 9 0 030339515 521150 9 10 SNOILONNA HIVd3H J IJIHJA AdIU3A 3080938 YLVA 5317 19 31 NOILINOI ONY 1904 NMOHS 080938 01 3LVIdW3L 193135 NMOHS STOIHSA 040938 01 145 42100 5 541 840 Sheet 13 of 14 Jul 30 1996 U S Patent 3NITLOH SOW WOH OL 0 35 0934 9 SIN3JAd S3lV ldW3l JWVN3H 31193514 WOHd SH398IUI OL Ad023 S3uniy33 1VI33dS SIN3A3 313IH3A H30H0233H Viva 2317 ldW3l TIY AV 1dSIG 35359 NOILVWHOJNI 3191IH3A 5 NOILVNYOSNI JILSONSVIO 319IH3A 521150 9 10 HIVd3H 3039515 SNOILONNS SINJAJ S3lV ldW3l 35793 WOHJ 51 3 3 3T9IHJA 139 521150 9 10 121 3 AdJIH3A SWISH H30H023H Ylva 3
2. ming on board vehicle controllers displaying service manual and service bulletin pages and ordering parts on line 8 Claims 14 Drawing Sheets U S Patent Jul 30 1996 Sheet 1 of 14 5 541 840 US Patent Jul 30 1996 Sheet 2 of 14 5 541 840 46 U S Patent Jul 30 1996 Sheet 3 of 14 5 541 840 RESET CONTROL LOGIC CONTROL 00 04 CONTROL Cr o i CONTROL i T 0 14 BAO BA14 E 25 08 015 BDO BD7 Qi 2 e m 9 321 x RAM CONTROL BAD BWA BCS 2 B B C S 579 5 E 52 SCALING TO 0 20V BUSt mE L LINE 1509141 QSM OF 68332 SPI TO VEHICLE I O CONNECTOR Fig 4 U S Patent Jul 30 1996 Sheet 4 of 14 5 541 840 STAAT USER SELECTS UPDATE SOFTWARE PROGRAM FROM MDS PROGRAM FROM MEMORY CARD CARD PRESENT PRESEN PROGRAM MENU USER SELECTS USER SELECTS MEMORY CARD MDS PAZSENT PRESENT Fig 8 PERFORM POST 60 STAND ALONE MAIN MENU 62 VEHICLE DIAGNOSTICS _ VEHICLES SUPPGATED HOW TO USE DABM UPDATE SOFTWARE VERSION UPDATE VEHICLE CONTROLLER 64 nA Co Po e 66 68 Mou MR ovate 59 _ OGG N OFF es BACK LIGHT 78 DISPLAY 76 Fig 5 U S Patent Jul 30 1996 Sheet 5 of 14 5 541 840 STAND ALONE MAIN MENU ECHO ON PC
3. FIG 3 is a plan illustration of the appearance of the back of the scan tool FIG 4 is a block diagram representing the architecture of the hand held unit FIG 5 is an illustration of the main menu of the hand held unit FIG 6 is an illustration of the hand held unit screen when selecting a vehicle system for monitoring FIG 7 is an illustration of the hand held unit screen when setting user options FIG 8 is an illustration of the main master station menu screen FIG 9 is a logic tree showing various features available FIG 10 is a sample diagnostic instruction screen from the master station FIG 11 is an illustration of a sample display screen from the master station showing technical information used dur ing diagnostics FIG 12 is an illustration of the master station screen when displaying logged data FIG 13 is an detailed illustration of the textual data display when dynamically displaying parameters on the master station FIG 14 is logic tree showing the data recording and logging functions FIG 15 is a logic tree showing how templates are stored and retrieved FIG 16 is an illustration of the master station screen as a custom template is being built FIG 17 an illustration of the service update screen and FIG 18 is a function diagram illustrating the different ways the hand held unit can be updated DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT As can be seen in FIG 1 the system of the prese
4. MORE LEFT RIGH Fig 10 U S Patent Jul 30 1996 Sheet 9 of 14 5 541 840 TEST IOAJ REPAIRING PASSENGER SIDE TIME LIMIT EXCEEDED Perform TEST 1A Before Proceeding PASSIVE BELT CONTROL MOOULE ET BALES MA lt val YL RIGHT SEAT BELT MOTOR RESERVE DRIVER 8 GROUND FUSED B RIGHT SEAT BELT MOTOR FORWARD DRIVER 5 541 840 Sheet 10 of 14 Jul 30 1996 U S Patent Z 0 o JHOW d 13H LE 300 53 q3SS3ud q3sv3 138 s35uno2 s3002 T 0355382 3mvA 195 108INO03 03345 N33S LON 2VLA 036 373 qnd TYLA GSV 593 4 SJA MNHJ d3Sv3igu 3mivA 8 10 1 02 09395 i 440 e OW SOLOS ONAN LOM UHO 340 3N7YA 4 0 0 1081 05 03305 862 0HV8 0 SIG 0 028 SLIOA 6 SN IVA SLIOA dVN _ 0 Bes 978 700 87 62 QVA 270 WNNIVA dvW AV 1dSIGQ VIVO IIWVNAG U S Patent Jul 30 1996 Sheet 11 of 14 5 541 840 MOS VEHICLE FRAME 0 5172000 03 MDS VEHICLE DA TIME 0 000 02000 03 92 8 0 58 MAP VACUUM 000 51 000 55 8 8 8 O O O O O O O O O O 70 40 0 ALL GEARS RELEASED OFF BLOCKED NO NO OFF FUEL MODE HELP MORE LEF ance 5 541 840
5. OFF ON DMM SPLIT WINDOW OFF DISPLAY UNITS METRIC KEY REPEAT OFF KEY FEEDBACK LED KEY FEEDBACK BEEP OFF DATE 11 30 92 TIME 12 25 1 2 3 4 5 6 7 8 4 Ta E ife e ADI E UP DOWN STOP ELP TOGGLE ON OFF BACK LIGHT 77 DISPLAY Fi g 7 STAND ALONE MAIN MENU ENGINE TRANSMISSION BODY SUSPENSION ANTI LOCK BRAKES PASSIVE RESTRAINTS THEFT ALARM SYTSTEM MONITORS CLIMATE CONTROL O Co 4 0 O1 GO PO 41 51 A 1 F2 F4 I E UP DOWN TURN STOP HELP TOGGLE ON OFF BACK LIGHT DISPLAY US Patent Jul 30 1996 Sheet 6 of 14 5 541 840 VEHICLE DIAGNOSTICS INFORMATION 011 TECHNICIAN ID REPAIR ORDER 2552555 MILEAGE ATM V 0 F3 MODE NO YES Heats d ERE F11 F12 MODE MAIN F6 ee E e FFig I7 CHRYSLER MOPAR DIAGNOSTIC SYSTEM MAIN MENU 0 DIAGNOSTICS TECHNICAL MENU INFORMATION SYSTEM SUPPORT VIEW SYSTEM PARTS TRAINING CATALOG MODE F4 2 150 YES vez HELP MORE LEFT RIGHT UP Y DOWN MENU F3 MODE F6 HELP MORE PRIN 8 5 541 840 Sheet 7 of 14 Jul 30 1996 U S Patent NNAW NIVW HIVd3u 521150 9 10 TIL AHVHBI 1 NOILVWHOJNI TV3INH931 CIVNOI LdO 9079195 IJIH3JA A3IH3A 030339515 AWNS 3 21150 9 1 0 01 SLHVd M3IA 521150 9 10 SAV 19510 31 15 AVIdSIG 3LVLS H
6. 476 3 1991 Abe 364 424 03 5 003 477 3 1991 Abe etal 364 424 03 5 056 023 10 1991 Abe 364 424 03 5 058 044 10 1991 Stewart et 364 551 01 5 077 670 12 1991 Takai et al 364 424 03 5 107 428 4 1992 Bethencourt et al 364 424 03 5 132 905 7 1992 Takai et 364 424 03 5 365 436 11 1994 Schaller et al 364 424 03 OTHER PUBLICATIONS Chrysler 1983 1988 Instruction Manual OTC Tool amp Equipment Division Sealed Power Corporation Feb 1988 entire book 1990 Domestic 3 in 1 Monitor 4000E Manual OTC Tool amp Equipment Division SPX Corporation Apr 1990 entire book MPSI Pro Link 9000 Manual for Chrysler System 1988 Chrysler Reference Manual for Snap On Scanner and 1990 Supplement Primary Examiner Collin W Park Attorney Agent or Firm Mark P Calcaterra 57 ABSTRACT The present invention relates to a system and method for diagnosing and isolating problems and for monitoring oper ting conditions on an automobile The system includes a hand held unit and a master station which can operate alone or in unison to accomplish functions such as logging and displaying data on a real time basis logging data remotely and displaying the data at a later time diagnosing fault conditions monitoring operating parameters reprogram
7. 9141 CARB cable has been selected because information from a standard engine controller is desired One end of the communication cable 16 is connected to the hand held unit 10 while the other end of the cable is connected to the vehicle 12 at the service connector interface usually located underneath the hood or the dashboard The hand held unit 10 measures the resistance of the cable 16 and determines that it is the ISO 9141 CARB cable and configures its commu nication protocol accordingly The hand held unit 10 once connected into the vehicle communication bus via the inter face sends commands to the engine controller and receives information back These commands are executed by the service technician by entering information in the hand held tool via the key pad As shown in FIG 5 upon powering up the hand held unit 10 the technician is presented with a menu display 60 providing a variety of options and function keys In this initial screen configuration the technician can select any menu item 62 by pressing the corresponding number 64 or can invoke a function such as help 66 screen toggle 68 illuminate back light display 76 and stop 72 by pressing the function F1 through F4 keys 74 80 respectively It should be noted that providing the generic key face labels FI through F4 82 88 while providing the function describer in the form of an icon located above the key allows the key pad to be freely configura
8. diagnostic procedures when attempting to isolate new fault conditions because actions taken by service personnel during previous service visits often affect the manner in which new problems are diag nosed For example through the service history recording mode the technician could indicate that using the hypo thetical O2 sensor situation the low O2 sensor reading problem was cured by reseating the O2 sensor connector In the event the vehicle is brought in for service at some later 10 20 30 35 45 50 55 65 10 date once again exhibiting faulty O2 sensor reading the stored service history information can be used during a diagnosis procedure to direct the technician to check the connection to see if the connector simply needs to be replaced As such one of ordinary skill in the art can appreciate how the storing of service history information in the vehicle controller s memory would be valuable and that the type of information stored can be customized to suit the specific needs of the situation Customized Templates From the foregoing discussion it can be appreciated that the hand held unit can monitor hundreds of different param eters on the vehicle For example the engine controller can provide information regarding fuel air ratio the transmis sion controller can provide transmission oil temperature the anti lock brake controller can provide wheel speeds and the body controller can provide informati
9. enter key 28 is pressed For example to select item number one vehicle diagnostics 62 the user can depress the numeral one on the key pad to move the highlight curser bar to the first item Similarly the user could use the directional arrow keys 27 to scroll the highlight bar to item number one Once the highlight bar is highlighting or pointing to the first item the user depresses the enter key to indicate that the first item is the desired item to be acted upon In this way accidental key strokes do not result in unintended activity In the event of an accidental key stroke the key stroke can simply be overridden by later key strokes or the character typed over by backing the curser over the character and typing a new character When in scan tool mode the user can step the hand held unit 10 to accomplish different procedures As shown in FIG 5 once the user selects the vehicle diagnosis option the next screen the user is presented with is the system selection screen shown in FIG 6 In this screen the user can decide which controller is to be queried Depending upon the system selected the user is presented with a variety of options for querying the controller as to stored diagnostic codes and monitoring operational parameters For example most engine controller store codes in the event that an operational problem is detected For the purposes of this discussion the error code stored by the engine controller will be assum
10. from DMM mode the technician simply depresses the DMM key again Thus the technician can be performing a diagnostic procedure on one vehicle and can interrupt that procedure to perform an electrical reading on a separate vehicle without requiring the technician to ter minate the diagnostic procedure on the first vehicle This feature further enhances the technician s ability to operate in an efficient manner Moreover by providing two sets of probes the technician can perform voltage differential tests quickly and easily For example to measure the voltage drop across an element using conventional means the technician would be required to use two separate meters and perform two separate read ings subtracting one reading from the other to obtain the difference By using the hand held tool in the DVOM mode the technician can simply attach each set of probes across the element in question and the hand held unit displays the voltages on the screen A further feature of the DMM mode is that each set of probes can be operated independently of the other That is one set of probes can be used to measure current draw while the other set of probes can be used to measure voltage drop Again the technician s efficiency is greatly improved by this feature Rather than requiring the technician to use separate meters to perform different types of readings or requiring the technician to perform these different readings sequen tially the techn
11. held unit could be reconfigured as will be described in greater detail in the service tool update section to provide the instruction sets necessary to execute such features Other Features of the Hand Held Unit As shown in FIG 7 the technician can also customize the manner in which information is presented to him For example he can change the display units from U S to metric and can change the date and time As before items from the menu are selected using the alphanumeric and or arrow keys Also the hand held unit has on board help procedures to aid the technician in the use of the hand held unit Help can be invoked one of two ways first by selecting the how to use unit item from the main menu as shown in FIG 5 or by pressing the help key at any time during operations Invoking help by pressing the help key during operations presents the technician with context sensitive help informa tion For example if the technician is using the hand held unit in DVOM mode invoking help will provide the tech nician with help screens related to DVOM mode Moreover from within help the technician can view help topics related to any aspect of the hand held unit by simply paging forward and backward and selecting new help topics Using the RS 232 connection the hand held unit can be connected to other devices such as a modem or a printer Master Station The master station 14 is designed to work in cooperation wi
12. indicating the update was successful The service manager next asks the technician to take an inventory of the stock room and order sufficient supplies for the next two weeks After checking the inventory the technician goes to the master station and places an order for air filters using the telephone link to the central warehouse from the on line parts catalog menu He then tells the manager that the order has been placed and the parts are scheduled to arrive next Tuesday It can be appreciated from the foregoing discussion that the system and method of the present invention is suited for use in a wide variety of applications Therefore one of ordinary skill in the art could readily adapt the concepts disclosed herein for use on any particular application We claim 1 A hand held service tool for monitoring an operation of a vehicle and for diagnosing problems with the operation of the vehicle the vehicle having at least one on board con troller for controlling the operation of the vehicle said 10 15 20 40 45 50 55 60 65 20 on board controller having communication bus for com municating with external devices and with other on board vehicle systems said communication bus having a prede termined unique communication protocol said service tool comprising at least one connection port for receiving a communica tion cable said communication cable having two ends where one end is connected to said se
13. using a flow chart form of representation Specifically any common computer can be used to built the diagnostic routine as a series of action blocks linked by logic flow paths These routines are then compiled by the master station as tokenized routines which are downloaded to the hand held unit for interpretation and execution Thus the support personnel writing diagnostic procedures need not be sophis ticated programmers rather the support personnel simply need to be able to visually describe what steps are to be taken and in what order since the master station and hand held unit are designed to use these forms of routines Thus each diagnostic routine can be thought of simply as a series of steps where the preceding step leads to the following step Where there is a choice of steps the preceding step simply leads to one of the alternative step based upon the techni cian s choice of action In the course of running a diagnostic routine the techni cian is required to perform certain tasks such as checking to see if a connection is secure or performing a voltage reading After taking the required action the technician can respond to queries from the system by entering yes or no or by entering numeric or alphabetic information via the keypad For example in diagnosing the hypothetical O2 sensor problem the system may require the technician to first check to see of the connection is secure Once he has checked the connec
14. 10 and the master station 14 When connected to the master station the hand held tool can operate as the controller talker or listener When in the controller mode of operation the hand held tool controls the operation of the master station and 10 15 20 30 35 45 50 55 65 6 performs diagnostic routines by querying the vehicle con trollers via the vehicle interface 42 In the talker mode the hand held tool 10 communicates with the master station 14 by transmitting information to the master station Similarly in the listener mode the hand held tool receives information from the master station via the interface 44 In this embodi ment there is no means for the master station to commu nicate directly with the vehicle Rather the master station downloads information to the hand held tool for running specialized diagnostic procedures and receives monitored vehicle perimeter information from the hand held tool via the communication link Scan Tool Mode As was discussed earlier the hand held unit 10 is capable of functioning as a diagnostic scan tool When in scan tool mode the hand held unit communicates with the vehicle 12 via the communication cable 16 Depending upon the type of vehicle being diagnosed and the particular controller within the vehicle being queried one of the six available cables as discussed earlier will be selected For the pur posed of this discussion it will be assumed that the ISO
15. 101H3A SINJA3 3 JIH3A 5327 19 31 LV 007 3A08V NMOHS 080338 01 91135 21 09 5 541 840 Sheet 14 of 14 Jul 30 1996 U S Patent WA Oy ONAN Mog Al 918 1337 SYOW d I3H 532 al Zd 4 9 300N Ed 338 3009 318 1 50115 94007 035079 5 15 1 915 WHV V SNLVLS 1909 NMOGLNHS OLNY HOSNJS 509 IJVHSXNVUJ HOSNdS 509 L3JVHSNWV I GIONS 10S 39Hfld dVA3 ATH 10 1 02 HOLIMS 3 105 100 4201 E c dWV 100 3201 2 HOSN3S 03395 3121 3 5 149 1 59315 IVI 3SN3S 39 110 110 1 ZDVINI 940 dW3L 930 05 35 dWil 1 8 110 1 1002 9N3 930 dW3L LNV 1009 9N3 SdIL 5110 27 2 Sd 5110 3u0SSddd 21 0 8 C ee C HB31N l0J 510 5110 520 LH9IH dVOV 37101 YNY dVOV 3101 1531 dVGV WH31l INO IHSIH Md NY8 199 IHVIS 910 65110 520 1531 0192 437 adVOV WH3l 9 011431 SL 10A SdL WNNIVA avW 0114182530 3 19IH3A 31V IdW3l WIL 3Wvu3 01 31 19 34 0 00 SW3LI VIVO 1293 3S 31Y ldW3l 5 541 840 1 HAND HELD AUTOMOTIVE DIAGNOSTIC SERVICE TOOL BACKGROUND OF THE INVENTION 1 Field of the Invention This invention r
16. A 01 521150 9 10 HA 01 521150 9 10 5 5 31715 dSNS HIV 521150 SISSVHI AV IdSIG 1 0 JINVNAG AVIdSIO 31V1S 9VH 521150 9 0 9V8 HIV AV dSIO 31715 S8V 521150 9 0 SAV 521150 9 0 134 5 ALVLS LJ3Hl SOILSONOVIG 1 3 10510 15 AVIdSIO 31 15 0089 521150 9 10 521150 9 10 009 X1V3 SJIISONSVIG 009 S9IISONSVIG X1V3 AVIdSIGO 3LVLS 521150 9 10 35385 NOILVWHOJNI 21150 9 10 HIVd3H SNDIISN S SOILSONOVIO A3IH3A rema u30u0338 viva 901 1 2 NOTLYWHONz 18099 5 518 ySINHO3L W31SAS W31SAS 521150 9 521150 9 10 5 0 VLVG SOILSONIVIG 3NI9N3 U S Patent Jul 30 1996 Sheet 8 of 14 5 541 840 CHRYSLER MOPAR DIAGNOSTIC SYSTEM FAULT SELECTION INSTRUCTION TO SELECT A DIAGNOSTIC TEST FOR FAULT S SHOWN AT RIGHT 1 ENTEH THE FAULT NUMBER 4 FOR FIRST FAULT 2 FOR SECOND FAULT 2 THEN PRESS THE F2 KEY ENTER 90 TO REDISPLAY FAULT DATA OTHERWISE TO SELECT A DIAGNOSTIC TEST FOR SPECIFIC SYSTEMS OR SYMPTOMS ENTER 0 ZERO THEN PRESS THE KEY FAULT 1 OF 1 START RUN COUNT 1 MAP VOLTAGE TOO HIGH SELECT TEST Xx MODE 5 1 HELP
17. United States Patent Gurne et al I ELLA Patent Number 4 Date of Patent 5 541 840 Jul 30 1996 54 HAND HELD AUTOMOTIVE DIAGNOSTIC SERVICE TOOL 75 Inventors Krzysztof Gurne Warren Raymond J Williams Farmington Hills John R Boldt Troy Robert L Barker Aubum Hills Gregory J Broniak Oxford Daniel J Marus Rochester Hills all of Mich 73 Assignee Chrysler Corporation Auburn Hills Mich 21 Appl No 83 050 22 Filed Jun 25 1993 51 GO6F 17 40 152 U S Ch tete 364 424 03 73 118 1 364 551 01 58 Field of Search 364 424 03 424 04 364 550 551 01 73 117 3 117 4 118 1 340 438 459 371 29 1 56 References Cited U S PATENT DOCUMENTS 31 582 5 1984 Hosaka et al 364 424 04 4 234 921 11 1980 Kinoshita et al 364 424 03 4 375 672 3 1983 Kato et al 364 424 03 4 602 127 7 1986 Neely et al 364 431 03 X 4 694 408 9 1987 Zaleski 364 551 01 4 831 560 5 1989 Zaleski 364 551 01 4 853 850 8 1989 Krass Jr et al 364 424 04 4 866 616 9 1989 Takeuchi et al 364 424 04 4 962 456 10 1990 Abe et al 364 424 03 X 4 964 049 10 1990 Abe et al 364 551 01 4 975 846 12 1990 Abe et al 364 424 03 4 975 847 12 1990 Abe 364 424 03 5 003
18. Using this mode not only can the basic diagnostic procedure stored in the hand held unit be updated but the actual boot memory of the hand held unit can be modified as well Thus using the scan tool update mode the basic operation of the hand held unit can be reconfigured as needed This allows the hand held unit to be updated quickly and easily as needed without requiring the technician to trade in scan tools or physically modify its configuration The hand held unit can also be reconfigured without the master station by connect ing it to a programming device via the RS 232 connection Selective memory updates can be accomplished by employ ing memory cards used in the expansion slots Overview A brief overview of how a technician would utilize all of these features and functions will now be provided For the purposes of this discussion it will be assumed that the technician has been presented with a customer complaint that the engine sometimes hesitates when accelerating from a full stop Based upon this information alone the technician cannot readily diagnose the problem Therefore the techni cian connects the hand held unit to the vehicle so that he may retrieve information from the engine controller The techni cian selects the appropriate cable and the hand held unit identifies the cable and modifies its communication protocol accordingly The technician selects the vehicle diagnosis option from the main menu and selects engine c
19. and enter the service information He reconnects the hand held unit to the vehicle and clears the codes Next as shown in FIG 17 he enters his ID number the VIN number the service order number and the mileage in hand held unit and flash programs the information into the engine controller s service log memory Before letting the car be released to the customer the technician checks to see if there are any service bulletins indicating an interim calibration update has been released Checking the technical library he learns that there has been a new set of anti lock calibrations released The technician places a memory module with the new calibrations into the expansion slot of the hand held unit As shown in FIG 18 the technician can load update calibrations into the hand held unit using a memory card or the master station Next the technician queries the car s antilock controller to see if it has the latest set of calibra tions The controller responds that it currently it running version 3 01b calibrations The hand held unit indicates to the technician that there are newer calibrations in the memory card and asks him if he would like to proceed with downloading these new calibrations to the anti lock control ler He responds yes and the hand held tool programs the anti lock controller s flash memory with the new calibra tions The controller sends a message to the hand held tool which is displayed for the technician
20. and has addressing and data control buffers 54 60 for communicating with the MC68332 con troller Likewise the MC68332 has interface buffers and A D converters Here both regular speed and high speed A D converters are used to ensure the data gathering process is rapid and accurate On board the hand held unit has 4 5 megabytes of memory One 250K block of memory is the boot ROM which can be reprogrammed or flashed to alter the operation of the hand held unit The boot memory contains the operating system and device drivers used by the hand held unit Another 250K block of memory is pseudo static memory with a ninety six hour storage life This memory is used for storing specialized diagnostic routines that have been downloaded to the hand held unit and for storing customized data gathering templates Another 1 Mb block of memory is also flashable and stores the diagnostic procedure information This memory can be reflashed via the master station link 18 from the master station 14 or can be reflashed using a memory expansion card in one of the expansion slots 31 48 or via the RS232 serial link 40 Another 1 Mb block of memory is pseudo static memory with an eight hour life This memory like the ninety six hour life memory is used to store information such as specialized diagnostic routines The final 2 Mb block of memory is RAM The master station connection port 44 supports GPIB communication protocol between the hand held tool
21. ated that the technician may find a need to define his own customized templates To do this the technician enters the customization mode and simply selects from lists those parameters he wishes to display in this customized template After selecting the items and building the template the technician can store this customized tem plate in the memory of the hand held unit by selecting the store option and entering an appropriate template identifier string For example the technician may simply want to store the template by identifying it as CUSTOM 1 or may wish to identify the template by his name the date or other such unique identifiers To enter characters for the template identifier string the technician simply presses the shift key while simultaneously pressing one of the alphanumeric keys to access letters rather than numerals For example to enter the first character of CUSTOM 1 the technician would hold the shift key down while depressing the key three times the first time he pressed the key the letter A would appear the second time the letter B would appear and the third time the letter C would appear In the event that the technician presses the key too many times the character sequence simply restarts Therefore upon the forth time the 5 541 840 11 letter A would again reappear To enter the next character the letter U the technician would depress the right arrow key to parse over to the
22. bination of hard coded and erasable ROM in addition to RAM The erasable ROM usually contains information such as calibration parameters Frequently after a vehicle has been introduced into production knowledge learned after use of the vehicle by customers in the field will necessitate a change in calibration parameters Rather than requiring the entire controller to be removed and replaced or the memory chips to be removed and replaced storing calibration param eters in erasable ROM allows the calibration parameters to be rewritten Here the hand held unit has the capability to write or flash erasable memory on the vehicle controllers To accomplish this the hand held unit has stored in its own internal memory the new information to be downloaded to the vehicle controller The technician enters the flash pro gramming mode by selecting the appropriate menu item from the display screen Once this mode is selected the hand held unit sends a control message to the controller to inquire as to the version and model number of the controller s memory Upon receiving the response from the vehicle controller the hand held unit determines whether or not the vehicle controller s memory needs to be updated If the memory does need to be updated the technician is presented with a screen indicating so and asking the technician whether or not he wishes to proceed Assuming the techni cian has indicated his desire to proceed by pressing the ye
23. ble through software For example since no action is being undertaken by the hand held unit when the initial menu is presented the F4 key need not be assigned the function of stop Rather at that stage the key may be de assigned in which case no icon 66 72 would appear over it and no action would be taken in the event of that key being stroked or the key may be reas signed in which case a new action and associated icon can be designated One of ordinary skill in the art can appreciate that the ability to assign reassign and de assign activities to the function keys allows the scan tool to be readily config ured for use with a variety of vehicles and vehicle controllers without requiring physical modification of the unit More over the icons can serve a dual function of being both a key identifier and an activity indicator In this embodiment the stop key serves not only to identify that the F4 key will invoke the stop function but also serves as an operation in progress indicator by blinking whenever an operation is 5 541 840 7 running If the technician invokes the stop function the icon stops blinking to indicate the operation has been stopped Action taken based upon the actuation of a function key 26 is immediate that is there is no need to press the enter key 28 to execute a function key In contrast while the alphanumeric keys 29 are used to enter characters the characters are not actually acted upon until the
24. cally hand held and interfaces to the automobiles on board con trollers via the vehicle communication bus usually tapping in to the bus at a connection point located beneath the dashboard For a scan tool to be a truly effective aid in diagnosing problems the scan tool must be able to commu nicate or talk to the various on board controllers regard less of whether the controller is manufactured by the auto mobile manufacturer or a supplier company One disadvantage of currently available scan tools is their inability to accommodate a wide variety of automobile models without requiring substantial hardware or software modification For most dealerships or service stations requiring the service technician to stock different scan tools for use on different vehicles is undesirable for reasons of cost limited storage space and difficulty for the service technician in remembering how to use each of these different scan tools Most currently available scan tools also rely upon fault trees printed in service manuals for guiding the tech nician through diagnostic steps These printed service manu als are costly to prepare and distribute and become soiled and torn through repeated use The manner in which these service manuals are supplemented is often problematic because these manuals are usually bound volumes and do not permit the easy substitution of updated pages A concern of service personnel and automobile manufac turers alike i
25. can be invoked two different ways First the technician may be requested to perform an electrical reading as part of one of the diagnostic steps For example using the O2 sensor hypothetical one of the diagnostic steps may require the technician to measure the resistance of the O2 sensor By placing the probes at the appropriate point on the O2 sensor the hand held unit will measure the resistance of the sensor and display that resis 10 15 20 25 30 45 50 55 60 65 8 tance reading on the screen Thus rather than requiring the technician to grab a separate ohm meter and perform the reading and input the measurement into the hand held unit integrating the DMM mode into the scan tool mode allows the measured reading to serve as the technician s response to the scan tool s query Additionally the technician can invoke DMM mode by simply pressing the DMM key on the key pad Invoking DMM mode simply suspends whatever operation the scan tool is currently engaged in for being resumed at a later time Specifically a split window is opened on the display screen the top half of the window shows the DMM mode while the bottom half of the screen shows the suspended operation The technician can toggle between DMM mode and the suspended operation by using the F2 toggle up down key When the technician toggles down to the operation window the operation is resumed and the DMM mode is suspended To completely exit
26. d As shown in FIG 12 the captured data is displayed graphically as well as numeri cally Moreover in the event that many parameters have been monitored certain of the parameters can be displayed graphically while the remainder of the parameters are dis played textually Similar to the concept of using templates for selecting the data to be logged the master station has templates that define which variables are displayed graphi cally as charts and which variables are displayed simply textually as numbers or as logic states Again the technician can retrieve predetermined templates or can define custom ized templates of his own Since the data displayed repre sents a snapshot in time the display cursor represented as a dashed line 120 on the data graphs indicates the point in time for which the variables are being displayed Thus the variables being displayed textually represent the value of those variables corresponding to the point in time where the cursor lies The cursor position is represented as a relative time value from the beginning of the window and is useful when attempting to determine the elapsed time between events or occurrences It can be appreciated that providing data logging and displaying capabilities with the hand held unit and master station allows the technician to gather a wealth of information without having to rely upon addi tional costly test equipment Besides charting previously logged information the ha
27. e monitoring the engine rpm as displayed on the master station monitor The master station monitor displays not only the engine rpm as a number along the right hand column but also displays rpm MAP sensor voltage fuel rate and throttle position as charts Unfortunately this information shows the car is operating just fine and fails to give him a clue as to the cause of the problem So the technician decides to suspend diagnostics and use the dynamic data display to check some things on his own The technician selects the data display feature from the menu FIG 14 is a logic tree which shows the organi zation of the menu selection process used by the technician He then looks through the predefined templates to see if there is one that suits his needs Finding there is not a template to his liking the technician selects the menu screen for building templates as shown logically in FIG 15 Once in the template building screen the technician moves the highlight bar from item to item selecting those he wishes to display during the dynamic data display operation As shown in FIG 16 the technician has selected some very specialized parameters such as cam shaft position and crank shaft position because he thinks there is a problem with the timing belt alignment While running the engine the dynamic data display on the master station presents the monitored parameters to the technician as a combination of graphs and numbers Unable to d
28. ed to be an error code associated with an O2 sensor reading below the required threshold Using the hand held unit the technician can send commands to the engine controller to have the engine controller relay its fault code information to the hand held unit for display In this instance such a command would result in the display providing a reference such as O2 sensor threshold low Based upon the fault codes read the technician can then decide how he would like to isolate the problem If desired he can connect the hand held unit to the master station to progress through a diagnostic routine wherein the technician is stepped through a series of actions which help the technician identify and isolate the cause of the problem In this instance the fact that the O2 sensor reading is abnormally low does not necessarily mean that the O2 sensor is bad Therefore the diagnostic actions prescribed in the diagnostic steps would walk the technician through the fault diagnosis procedure to aid him in isolating the problem The manner in which the hand held unit and the master station cooperate when running diagnostics will be described in greater detail later Digital Multi Meter Mode Another important feature of the hand held unit is its ability to operate as a stand alone digital multi meter DMM In this embodiment the hand held unit is provided with two sets of probe inputs 32 38 to allow measurements at two test points Operation as a DMM
29. elates generally to a system and method for monitoring automobile operating parameters and for diagnosing operational errors and more particularly to a system and method for retrieving diagnostic codes from automotive control systems for monitoring automotive operating parameters for performing diagnostic inquiries and for logging and later downloading operational variables 2 Description of the Related Art In the field of automotive service it has become increas ingly important to be able to monitor the operation of major automobile systems such as the engine transmission and braking system on a real time basis diagnosing and repairing operational problems Since these major systems are now usually controlled either entirely or in part using an microcomputer the on board ability of the controllers to store operational information and error codes for later retrieval has been exploited to improve the accuracy with which service personnel diagnose problems However these controllers have limited on board memory for storing these operation parameters Moreover relying solely upon on board capabilities does not allow the service procedures to adapt to information learned after the product has been out in the field for a while Thus it is preferable to supplement on board capabilities with auxiliary diagnostic systems One commonly employed auxiliary diagnostic system is commonly known as a scan tool The scan tool is typi
30. eters before during and after the trigger can be retrieved for later inquiry Such information often proves valuable when diagnosing problems which manifest themselves only while the vehicle is being driven Expansion Modules As was initially discussed the hand held unit has expan sion ports for receiving expansion modules These modules can take a variety of forms and can include not only 10 15 20 25 30 35 45 50 55 65 12 additional memory but interface circuitry for allowing the hand held unit to communicate with different devices Pro viding for the expansion ports and expansion module capa bilities allows the hand held unit to grow as technology evolves without requiring the entire scan tool to be traded in or reconfigured Also new features can be incorporated into the service tool system more economically because only the circuitry for the new feature need be designed the hand held unit itself does not require rebuilding or redesign For example an expansion module for performing radio fre quency measurements may become available The expan sion module would contain the circuitry needed to perform such a specialized measurement and would interface to the hand held unit via the expansion port To allow the hand held unit s controller to control the expansion port and interpret the measured information operating routines can be down loaded into temporary memory or the memory of the hand
31. for storing said custom templates for future use 6 The invention according to claim 1 wherein said service tool includes key pad means for directing the opera tion of said service tool display panel means for displaying information in response to the operation of said service tool 5 541 840 21 page means for enabling the user to back track through a diagnostic procedure in order to modify an earlier diagnostic selection 7 hand held service tool for monitoring an operation of a vehicle and for diagnosing problems with the operation of the vehicle the vehicle having at least one on board con troller for controlling the operation of the vehicle said on board controller having a communication bus said ser vice tool comprising at least one connection port for receiving a communica tion cable having two ends wherein one end is con nected to said service tool at said connection port and the other end is connected to said vehicle at a connec tion port on said vehicle communication bus at least one measuring circuit for measuring at least one of a voltage across and a current through at least one electrical circuit component on the vehicle two sets of input probes connected to both said measuring circuit and said electrical circuit component and display screen means for displaying voltage and current data received from said measuring circuit 8 A method of operating a service tool for monitoring an operation of a vehic
32. hronously that is as the technician steps through the diagnostic pro cedures the hand held unit and master station step through the procedure together In this way the technician can either use the key pad on the hand held unit or the keyboard of the master station to step through the diagnostic procedure More importantly however because they are stepping through the procedures together the display of the master station displays the graphical and textural reference from the technical information library which corresponds to the diag nostic step being performed For example as shown in FIGS 10 and 11 the master station display informs the technician of the action required for the particular diagnostic step while presenting a graphic representation of the vehicle or systems in question Thus where the technician may have previously relied upon a printed manual for a graphic representation of the components he must locate the master station displays these graphical representations in conjunc tion with the instruction text for each of the diagnostic steps To appreciate this feature it should be realized that the 5 541 840 15 technician still could performs diagnostic tests without link ing the hand held unit to the master station If he chose to operate in this manner he would refer to a printed service manual or would invoke diagnostic mode on the master station without linking the hand held unit and he would manually page
33. iagnose the problem by simply running the engine in the garage the technician decides to use the data 5 541 840 19 logger as he drives the car around the service station s parking lot The technician disconnects the hand held unit from the master station but leaves it connected to the car as he drives the car around Bringing the car to a stop and beginning to accelerate the car goes over a bump and the technician experiences a loss of engine power At that moment the technician presses the read hold key on the hand held unit s keypad to store this window of information He drives the car back to the garage disconnects the hand held unit and walks over to the master station which has been since rolled to the other side of the garage by another technician Reconnecting the hand held unit to the master station the operational parameters are displayed on the monitor for viewing At this point the information provided to the technician allows him to diagnose the fault fuel flow rate dropped to zero when the lag was experienced and the fuel pump voltage dropped below the minimum threshold a few seconds prior to the fuel lag Checking the connector to the fuel pump the technician finds that the power lead has become corroded and needs to be cleaned He cleans the connection and reseats the connector Having successfully diagnose the problem the technician then updates the engine computer to erase the fuel error air fault flag
34. ician can simply attach the probes to the items in question and perform these different types of readings simultaneously A further feature of the DMM mode is that single probe measurements are possible This feature is especially impor tant when attempting to measure electrical characteristics of devices in hard to reach locations Because the hand held unit can be connected into the vehicle communication bus via the communication link the hand held unit is provided with system and chassis ground via the communication link obviating the need to provide a separate measurement ground via the test probe Therefore using only one lead of the test probe voltage and current measurements can be obtained using the signal or chassis ground provided via the communication link as the measurement ground Controller Update Mode The hand held unit is also capable of downloading infor mation to the vehicle controllers for the purpose of updating these controllers For example most controllers utilize a combination of ROM and RAM The ROM contains the control algorithm and calibration parameters while the 5 541 840 9 RAM contains operational parameters When controllers were first being used on automobiles the ROM was hard coded that is the ROM was fixed and unchangeable Likewise RAM was volatile and any information stored in RAM would be lost if the controller power supply was interrupted Today automotive controllers rely upon a com
35. ins through its technical informa tion library mode In this mode the technician can access service manuals and service bulletins which are stored on the CD ROM for display on the monitor This mode has several benefits First is the advantage of obviating the need for paper manuals and service bulletins which often become torn soiled and lost over time Also because the information is stored electronically and retrieved only as needed there is no need to have book shelves for storing these items Moreover as information changes and requires updates new pages can be added electronically by updating the CD ROM without requiring the technician to physically insert pages into a printed manual Updating technical information can also be accomplished by supplementing the information on the CD ROM s through information stored on floppy disks as well as information available via telecommunica tion download links such as modems In this embodiment the master station can be connected to any conventional phone line for communicating with a remote host computer for downloading update information Once the information is downloaded into the master station the updated informa tion can be stored in the internal memory of the master station or on a floppy disk By allowing updated information to be provided via these different methods the master station technical information library can be easily maintained in an up to date state Anothe
36. ion library for more assistance Using the keyboard on the master station the technician enters the vehicle type and model year to see if a service bulletin has been issued regarding this problem The master station searches its CD ROM data base for a relevant bulletin and presents the information to the technician on the monitor In this example the bulletin informs the technician that problems such as this have indeed been experienced in the field and a new diagnostic procedure has been provided Upon learn ing this the technician connects the hand held unit to the master station via the communication link and using the keyboard request the master station to download the new diagnostic procedure to the hand held unit The master station relays the information to the hand held unit and the new diagnostic procedure is stored in the hand held unit s eight hour memory The technician then begins executing the new diagnostic procedure Since the master station is connected to the hand held unit while the technician is executing the diagnostic procedure the master station displays for the technician information such as the particular step required and the appearance of the components in question As part of the diagnostic procedure the technician is requested to turn on the engine and idle it at 2 300 rpm The master station recalls a predetermined template for displaying the dynamic data The technician enters the vehicle and starts the engin
37. ld unit by its nature has only a limited amount of memory available the master station is used to store all diagnostic procedures for all the various controllers and vehicles which are supported by the service station or dealership As the technician performs a diagnostic proce dure on the vehicle the hand held unit will request the master station to send it additional diagnostic information in the event the hand held unit s memory does not contain the required diagnostic procedures This information is then downloaded to the hand held unit via the communication link 18 and stored in the eight hour memory It can be appreciated that the information downloaded from the master station to the hand held unit requires a substantial amount of memory Here because there is a limited amount of memory available for storing these down loaded routines the hand held unit purges from its memory those routines and information used the least in favor of storing the newly downloaded information This scheme is often referred to as a least recently used memory man agement scheme and allows information which is rarely used or which have never been used to be removed from memory rather than a first in first out scheme which automatically removes the longest stored or oldest infor mation from memory simply because it has been there longer When in diagnostic mode it is important to realize that the hand held unit and master station operate sync
38. le and for diagnosing problems with the operation of the vehicle the vehicle having at least one on board controller for controlling the operation of the 5 10 15 20 22 vehicle said on board controller having a communication bus for communicating with external devices and with other on board vehicle systems said service tool including an off board controller having a memory means and a display screen communication means connecting said service tool to said vehicle communication bus said method of operating comprising the steps of automatically determining an appropriate communication protocol for communication between said on board controller and said off board controller based upon a parameter associated with said communication means wherein said parameter includes unique electrical char acteristics transmitting vehicle trouble code date to said service tool from said on board controller via said communication means using said determined communication protocol erasing at least one vehicle trouble code at said on board controller responsive to a command signal input to said service tool in response to a diagnosis decision corre sponding to said vehicle trouble code data and storing in said on board controller service history infor mation from said service tool
39. nd held unit and master station cooperate so that operating 5 541 840 17 parameters can be displayed dynamically As was the case before the master station displays some of the variables as charts and other of the variables textually depending upon the template selected In the dynamic data display mode many more parameters can be monitored than would be possible using the data logger alone as shown in FIG 13 That is because the variables are being displayed dynami cally rather than being stored and the amount of informa tion gathered need not be limited by the amount of on board memory available in the hand held unit However if desired the dynamically displayed data can be logged in the master station and stored in the master station s internal memory or on a floppy disk for later reference Likewise the master station has capabilities for creating customized templates which can be stored using string identifiers and retrieved for later use Scan Tool Update Mode Besides being able to dynamically download information to the scan tool for use in diagnostic procedures the master station can also reprogram the hand held unit in a manner similar to the way the hand held unit can reprogram con trollers on the vehicle When the hand held unit is connected to the master station the technician can select the update scan tool option from the menu Once in this mode the hand held unit s memory can be reconfigured accordingly
40. ne or more of said vehicles wherein once a vehicle is selected for monitoring and one of the corresponding communication cables is connected to said service tool and said vehicle communication bus said detection means further identifies said unique electrical characteristics of said connected cable whereby said protocol means matches the communication protocol unique to the selected vehicle 3 The invention according to claim 1 wherein said service tool includes means for causing service history information to be stored in said on board controller 4 The invention according to claim 3 wherein said means for causing service history information to be stored in said on board controller includes key pad means on said service tool for entering said service history information display panel means on said service tool for displaying said service history information as it is being entered from said key pad means and signal conveying means for transmitting said entered service history information from said service tool to said on board controller through said communication cable 5 The invention according to claim 1 wherein said service tool includes key pad means for directing the opera tion of said service tool display panel means for displaying information in response to the operation of said service tool logic means for enabling the user to create custom templates of only selected parameters to be displayed on said display panel means and
41. next character position and would depress the shift key while simultaneously depressing the 7 STU key three times Once the identifier string has been built the technician can enter that name by simply depress ing the enter key The hand held tool stores the customized template in the ninety six hour memory according to the identifier string Alternatively the technician can direct the hand held unit to store the template on a memory cartridge or can upload the template to the master station for storage on its internal hard drive or on a floppy disk During later operations the technician can retrieve this customized template by selecting it from the list of available templates Data Logger Another important feature of the hand held unit is its ability to function as a data logger Often when conducting diagnostic procedures the technician will be unable to recreate in the garage the problem of which the customer is complaining Rather many problems often manifest them selves as the car is driving over bumps or underneath power lines conditions which cannot be recreated in a garage Therefore the technician can use the hand held tool to monitor vehicle parameters as the vehicle is being driven By monitoring vehicle parameters on a real time basis the technician can obtain a better understanding of the condi tions which may be causing the problem To operate the hand held unit as a data logger the technician selects the data l
42. nit as a data logger which will be described in greater detail later Along the top of the hand held unit 10 there are connection points 32 38 for electrical probes an RS 232 connection 40 for communicating with other computers and computer peripherals a vehicle inter face connection 42 and a GPIB master station interface connection 44 On the back of the hand held unit a remov able cover 46 protects a peripheral expansion port 48 As will be described in greater detail later the peripheral expansion port accepts an expansion module which allows the hand held tool to be compatible with many other devices such as a computer disk drive a wider variety of vehicle controllers and other types of measurement tools The vehicle interface capabilities of the hand held unit will now be described in greater detail The vehicle interface connector 42 is a thirty six way connector The hand held unit 10 is interfaced to the vehicle 12 via the vehicle interface cable 16 In this embodiment the vehicle interface 44 is adapted to work with a variety of interface cables Specifically six different types of cables are currently sup ported All of these cables while utilizing the same thirty six way interface support different communication protocols For example an ISO 9141 CARB cable is an asynchronous full duplex serial communication link configurable to a variety of baud rates such as 976 7812 5 62 5K and 104 baud rates with signal levels va
43. nloaded later for inquiry The master station can plot and interpret vehicle information from the scan tool whether real time or logged to aid the technician in diagnosing the cause of a problem One advantage of the present invention is that it is suited for use in conjunction with a wide variety of automobiles and automotive controllers reducing the need to replace scan tools as model years change and reducing the need to carry several different scan tools for communicating with different controllers Another advantage of the present invention is that the logging capabilities allow the technician or the customer to drive the automobile while monitoring and recording operation parameters as the problem occurs Still another advantage is that the master station allows the scan tool to be updated quickly without requiring new scan tools to be purchased when service information is updated Another advantage is that the master station reduces the reliance upon printed service manuals and loose page ser vice updates BRIEF DESCRIPTION OF THE DRAWINGS Other objects features and advantages of the present invention can be appreciated by referencing the following description of the presently preferred embodiment in con 5 541 840 3 junction with the drawings where FIG 1 is an illustration showing how the scan tool interfaces to the automobile and master station FIG 2 is an orthogonal illustration of the appearance of the scan tool
44. ntly preferred embodiment includes the hand held unit 10 which connects to the car 12 and the master station 14 via cables 16 18 The hand held unit 10 has specialized hardware and software on board for communicating with the various controllers on the car As will be described in greater detail the hand held unit 10 is capable of operating as a scan tool volt ohm meter and data logging unit by itself without requiring support from the master station When the master station 14 is connected 18 to the hand held unit 10 the hand held unit can serve as a smart interface between the master station 14 and the various controllers on the car 12 The master station itself is capable of downloading alternative diagnostic routines to the hand held unit 10 as needed while also providing the ability to update and or reconfigure the internal memory of the hand held unit The master station further provides interactive data charting capabilities The master station 14 also serves as a paperless service manual providing detailed pictorial and textural service information These and other features of the hand held unit 10 and the master station 14 will be described now in greater detail Hand Held Unit As can be seen better in FIGS 2 and 3 the hand held unit 10 is approximately 14 inches long 6 inches wide 2 5 10 20 25 30 35 45 50 55 65 4 inches tall and weighs approximately 4 lbs The face of the hand held unit incl
45. ogging option from the menu With the hand held unit connected to the car via the communication ink all of the parameters which were avail able for measurement during measurement and testing pro cedures are also available for logging Therefore the tech nician can select a predefined data logger template or can establish his own customized template in a manner similar to that which was previously described The template defines which variables are to be monitored Depending upon the number of variables to be monitored the hand held unit s internal memory samples these parameters and stores them for later retrieval In this embodiment since the hand held unit s memory is limited the logged data is stored in memory using a shift register concept That is as new data is logged older data is overwritten Therefore in the hand held unit s memory the logging information stored repre sents a snapshot or window of information As the technician drives the car around and the hand held unit logs data the technician can que the hand held unit to freeze a window of information This is accomplished by the technician triggering the read hold key on the keypad When the trigger is activated the hand held unit stores a window of information in memory such that the values of the monitored parameters around the time of the trigger are stored In this way the hand held unit stores the parameters so that the behavior of the monitored param
46. on on whether lamps are burned out or doors are opened Thus it is possible for the hand held tool to gather from a variety of sources information necessary to diagnose problems Moreover there may be instances when the service technician desires to monitor information from these various sources simulta neously during service and maintenance routines Therefore the hand held unit has been provided with the capability for the technician to develop customized reading templates for gathering such diverse information quickly and efficiently To develop a customized template the technician simply selects the menu item for using and storing templates By selecting this item the hand held unit is placed in a pro gramming mode of sorts The technician can retrieve predefined templates from memory and can store and retrieve customized templates as well To retrieve a predetermined template the technician simply selects that template from the selection list For example such a predetermined template may provide infor mation as to whether or not the brake pedal is depressed and whether or not the brake lamps are illuminated for the purpose of diagnosing wiring or lamp failures While such a predetermined template is usually retrieved automatically during the process of performing a diagnostic routine in the scan tool mode the technician can selectively retrieve predetermined templates for use outside of the scan tool mode It can also be appreci
47. ontroller from the sub menu The hand held tool queries the engine controller and informs the technician that there is a fault code for lean air fuel ratio The technician then begins checking the various sub components on the engine to locate the cause of the fault During the course of his diagnosis procedure the technician uses the hand held unit to measure the resistance of the MAP sensor The technician inserts the voltage probes into the hand held unit and places the other end of the probes across the MAP sensor The resistance of the MAP sensor is read and displayed for the technician and the fault diagnosis procedure continues 10 15 20 25 30 45 50 55 60 65 18 While the technician is diagnosing the problems on the customer s vehicle the service manager interrupts the tech nician and ask the him to perform a voltage reading across an old car battery which has been in storage Without having to disconnect the hand held unit from the car the technician selects the DVOM mode on the hand held unit and measures the voltage across the battery as requested The hand held unit displays the voltage reading for the technician Once the technician is done with his side task he simply presses the key pad to resume the fault diagnosis procedure After having proceeded through the fault diagnosis pro cedure without yet locating the problem the technician turns to the master station to access the technician informat
48. r advantage of the master station technical infor mation library is that because the information is stored electronically it can be sorted and filtered before being presented to the technician That is the technician can indicate that he is looking for information related to a certain vehicle or a certain component and the master station can retrieve those portions of the technical information library relevant to the technician s query without requiring the 30 35 45 50 55 65 14 technician to leaf through otherwise irrelevant information This has a great advantage to printed media since the technician must physically parse through the pages to find the relevant information when using printed manuals The technician can also search for information by the vehicle information number VIN in a similar matter As part of the technical information library the master station also includes an on line parts catalog Using this feature the technician can view various components of the automobile and can place orders for parts that the service Station may not carry in stock When connected into a common phone line the master station can automatically place orders for these parts using an electronic ordering system Diagnostics Mode When connected to the hand held unit the master station augments the hand held unit s diagnostic capabilities These features are represented as a logic tree in FIG 9 Because the hand he
49. rly familiar to technicians a scan tool which provides these added features would prove very helpful SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a system and method for monitoring the operation of a vehicle on a real time basis and for providing sophisticated problem solving capabilities for accurately diagnosing and repairing problems The present invention employs a hand held scan tool and a master station to provide improved service support and capabilities The scan tool of the present invention is adapted to interface to the automobile and communicate with the various on board controllers to moni tor the operation of the vehicle on a real time The scan tool is adapted to be compatible with a wide variety of makes and models of automobiles and vehicle systems reducing the need to replace scan tools as model years change The scan tool can be updated quickly and easily from the master station or from memory cartridges The master station of the present invention is adapted to interface to the scan tool and provides sophisticated updating and diagnostic capabilities not feasible to include in the scan tool itself The master station reduces the need to rely upon printed service manuals when using the scan tool reducing printing and distribution costs The scan tool is further adapted to provide data storage capabilities allowing the status of monitored operating parameters to be logged and dow
50. rvice tool at said connection port and the other end is connected to the vehicle at a connection port on said vehicle communi cation bus detection means integral with said service tool and con nected to said service tool connection port for identi fying said communication cable wherein said detection means identifies unique electrical characteristics of the connected communication cable protocol means responsive to a signal from said detection means for matching a communication protocol of said service tool with a communication bus protocol asso ciated with the communication bus which is connected to the detected communication cable and logic means for sending inquiry commands to said vehicle controller from said service tool via said communica tion cable over said vehicle bus using said communi cation bus protocol said inquiry commands causing said vehicle controller to communicate vehicle opera tional information to said service tool via said commu nication cable over said communication bus 2 A service tool as set forth in claim 1 adapted for monitoring the operation of more than one vehicle each vehicle having on board controllers and communication buses having protocols unique from one another there existing more than one communication cable suitable for being received at said service tool connection port each said communication cable having unique electrical characteris tics from each other and suitable for use with o
51. rying between an idle condition of twelve volts and zero volts Similarly an SCI I cable is an asynchronous duplex serial communication link configurable to baud rates such as 976 7812 5 and 62 5K baud with the signal levels varying from an idle of zero volts to five volts Both the SCI I and ISO 9141 CARB communication links utilize the standard ten bit non return to zero NRZ data format with one start bit eight data bits and one stop bit Yet another cable communicates using a contention based class B multiplexed bus transferring data at 7812 5 baud via a voltage differential generated across the bus which is biased to 2 5 volts Because the same connector interface 42 is used to support all of these various communication protocols the hand held tool 10 must be able to recognize which cable is 5 541 840 5 connected at the interface 42 and adapt its communication protocol accordingly In this embodiment this is accom plished by ensuring each of the unique cables has a unique resistance associated therewith This unique resistance is measured and recognized by the hand held unit 10 so that it may identify the cable to which it is connected and adjust its communication protocol accordingly Specifically in this embodiment two pins of the connector provide the resis tance signal feed The resistance signal feed is interfaced to the control logic circuitry so that the resistance may be measured and compared to predetermined value
52. s key the hand held unit sends the commands to the vehicle controller necessary to reconfigure the programmable ROM to reflect the new calibration values The process of sending the appropriate commands and calibration data to a vehicle controller and verifying that the information has been cor rectly received and stored is well within the grasp of one of ordinary skill in the art and therefore will not be described in detail herein Once the commanding writing and verifi cation process has been completed the hand held unit displays to the technician whether or not the vehicle con troller update procedure has been successful Service History Recording Mode The hand held unit is also capable of recording service history information on the vehicle controllers Similar to the process of updating calibration information the hand held unit can send commands to the vehicle controller to store information regarding service procedures For example when in the scan tool mode the technician is reading fault code information from the vehicle controller in an attempt to diagnose and isolate the cause of the fault condition Once the technician has successfully isolated and remedied the problem the service history recording mode of the hand held unit allows the technician to erase the fault code from the vehicle controller s memory and store codes indicating what procedures were performed and when Such information proves very useful during later
53. s corre sponding to the unique resistances for the various cables In this embodiment the resistance values of the various cables have been established such that given measurement toler ances there is no chance of overlap between the resistance values which may otherwise cause an erroneous cable identification Specifically a cable for communicating with the engine controller has a nominal resistance of 3 010 ohms a cable for communicating with the body controller has a nominal resistance of 14 000 ohms and the J1962 cable has a nominal resistance of 44200 ohms Once the hand held tool 10 determines which vehicle interface cable 16 is connected to it the hand held tool 10 adapts its communication protocol to match the protocol of the cable This feature allows the hand held tool to be used with a wide variety of vehicles and vehicle controller systems such as engine transmission anti lock brake and body controllers The actual architecture of the hand held unit s controller can be found in FIG 4 As shown here there are two microcomputers on board an ST9 50 and an MC68332 not shown The ST9 microcomputer commercially available from S Thomson of Texas is the communications coprocessor while the MC68332 microcontroller available from Motorola of Illinois performs the diagnostic and data gathering features The ST9 controller has A D converters 52 for measuring and scaling information from the vehicle interface connector
54. s the need to ensure problems are diagnosed accurately and promptly For the service technician the customer who brings the vehicle in for service often has a very vague description of the problem it makes a clickity noise sometimes that is not currently manifesting itself when the vehicle is brought in and that the technician finds difficult to recreate It would be easier for the technician to accurately diagnose the cause of a problem if he can monitor the operating conditions of the vehicle while the problem is 15 20 25 30 45 50 55 65 2 manifesting itself However this is difficult to achieve because the technician cannot easily drive around with the customer and the customer cannot afford to leave the vehicle with the technician for days at a time For the technician it is often expedient to simply replace parts which seem to be the likely culprits in the hopes that the tried and true method will solve the problem However this increases warranty costs to the manufacturer because parts that may not be faulty are replaced regardless Also when parts are replaced and the problem still remains the customer become frus trated and often vents this frustration on dealership person nel Therefore it would be preferable if tools were provided to the technician which improves his ability to monitoring problems as they occur and to accurately diagnose and repair the cause of the problem Since scan tools are fai
55. sensor threshold reading if the technician originally responded to the ques tion of whether or not the connector was secure by pressing the yes key but he later determines that the connector while appearing to be secure was actually loose the tech nician can back track through the diagnostic steps to that screen and modify his answer to no The ability to back track and modify selections is made possible by the way the diagnostic routines are built and stored as tokenized modules rather than conventional sequentially processed routines or programs As one or ordinary skill in the art can appreciate allowing such back tracking without requiring the entire diagnostic procedure to be re initiated greatly improves the efficiency with which the technician can diagnose and isolate problems One of ordinary skill in the art can also appreciate that depending upon the vehicle controller being monitored and the type of problem which is being diag nosed the diagnostic procedures presented to the technician will vary accordingly Data Recorder And Display Mode When used in conjunction with the hand held unit the master station can serve as a data recorder and display unit As was discussed earlier the hand held unit can serve as a stand alone data logger for capturing vehicle information as a vehicle is being driven To display this information the hand held unit is connected to the master station and the display stored data option is selecte
56. talog and host update link However when connected to the hand held unit the master station is also capable of acting as a data recorder diagnostic station and hand held unit update host The master station besides having a GPIB interface for commu nicating with the hand held unit also has an RS 232 interface for communicating with other service tools In this embodiment earlier generation hand held units communi cated only via RS 232 Therefore the master station of the present invention can communicate with older units via the RS 232 while also communicating with the hand held unit via the GPIB link Regardless of the mode of the master station the user interface appears similar to that of FIG 8 As can be seen the user interface is both graphic and textural in nature where the highlight bar can be moved between items to select the desired action To move the highlight bar the technician can use the keys of the keyboard or if the hand held unit is connected to the master station can use the key pad on the hand held unit Similar to selecting items on the hand held unit the technician can parse through screens using directional arrow and paging keys Also as was the case with the hand held unit the technician can backup through procedures in the event he changes his mind about the course of the action selected Technical Information Library The master station obviates the need for printed paper manuals and service bullet
57. th the hand held unit in performing sophisticated diag nostic procedures and the like and can operate indepen dently of the hand held unit as a reference resource for the service technician The master station itself is approximately 4 feet tall with a base dimension of approximately 36 inches by 24 inches The heart of the master station is an IBM compatible computer with an internal hard drive The master station also includes a 19 inch monochrome video monitor 100 for graphics display a keyboard 102 a floppy disk drive and CD ROM drives 104 and communication cables 18 The master station cart 106 has casters 108 at the base for allowing the station to be rolled from place to place The internal memory of the computer contains the master station operating system while the CD ROM drives are used to store service and diagnostic information and the like The floppy disk drive accepts standard 3 inch disks and is used for things such as swapping information between stations and for performing backups and storing seldom used information while the larger capacity hard drive is used for storing information such as diagnostic results and custom 5 541 840 13 ized test procedures The master station can operate alone or in conjunction with the hand held unit 10 Specifically regardless of whether the master station 14 is connected to the hand held unit the master station is capable of operating as a technical information library parts ca
58. through the diagnostic procedure step by step Thus the technician would have to refer to the diag nostic procedure for the required action and would then use the hand held unit to gather measurements required for that particular step Once he completed that step he would flip to the next step and perform the required action Here by linking the master station and hand held unit together and by having them step through the diagnostic procedure synchro nously the technician is relieved of having to manually parse through the test procedure Also another important feature of the system is that when in diagnostic mode the master station displays test results just as the hand held unit would display test results based upon the diagnostic procedure being performed The hand held unit actually controls the progress of the diag nostic routine Any entries on the key pad are sent from the hand held unit to the master station and back from the master station to the key pad as a synchronizing handshake Any entries on the keyboard of the master station are sent from the master station to the hand held unit which actually acts upon the command The diagnostic routines are actually tokenized routines which are interpreted by the hand held unit s MC 68332 interpreter This is in contrast to diagnostic routines of other commercially available systems which are actually coded programs Here new diagnostic routines can be written or built
59. tion the technician responds to the system by press ing the yes or no key accordingly Similarly the system may require the technician to measure the resistance of the O2 sensor By placing the probes of the hand held unit on the O2 sensor connection points the hand held unit measures the resistance and displays the reading The technician can then indicate the reading appears to be accurate by pressing the yes or no key The various diagnostic steps can be though of as pages where paging down involves moving on to the next step and paging back involves back tracking to the previous step in 10 15 20 30 35 45 50 55 60 65 16 the sequence The technician can control his progress through the diagnostic steps by using the page up and page down keys By allowing the technician to freely parse through the diagnostic steps the hand held unit provides greater flexibility for the technician in diagnosing the prob lem For example after progressing through the diagnostic steps for a while the technician may determine that he is proceeding down a less than fruitful course of action In such an instance the technician can use the page up key to back track through the diagnostic procedures This allows the technician to back track for example and modify his response to previous queries or select a different course of action when he was presented with several choices Thus using the previous example of a low O2
60. udes a display screen 20 and a keypad 22 The display screen in this embodiment is a backlit LCD display having a resolution of 320x200 pixels with an overall screen dimension of 4 inches wide by 3 inches tall The screen is tilted at a slight angle to facilitate viewing from an angle such as would occur if the unit were placed on a work table or on the car while being used The key pad is formed from a flexible plastic membrane with the key boundaries 23 embossed and the characters 24 printed on the surface The key pad includes four function keys 26 four directional arrow keys 27 used to parse through character strings and step through logic sequences two enter keys 28 to indicate a command is to be entered ten alphanumeric keys 29 for entering letters numbers and characters and eight special function keys 30 used for responding to queries and the like The key pad is a membrane key pad in this embodiment because of the harsh environment in which the hand held tool operates By utilizing a membrane the actual key contact points are protected from contamination by dirt and moisture Moreover utilizing a membrane key pad helps reduce the likelihood that keystrokes are entered uninten tionally At the base of the hand held tool 10 an expansion slot 31 approximately 2 inches long and 1 4 inch wide is adapted to receive conventional PCMCIA card memory expansion boards The memory expansion cartridges are useful when using the hand held u

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