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Home/Isuzu/Rodeo/Isuzu Rodeo II (1998-2004)/Repair manual/Testing & Diagnostics/Engine Controls - Self-Diagnostics - 3.2L & 3.5L: Other
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Engine Controls - Self-Diagnostics - 3.2L & 3.5L: Other Isuzu Rodeo II

Testing & Diagnostics ~5433 words

TRIP DETECTION LOGIC

OBD-II data streams are prioritized. When 2 messages attempt to establish communications on a data line at the same time, only the message with higher priority will continue. A new segment of the software called the Diagnostic Executive coordinates the protocol for recording and displaying diagnostic procedures.

Trip is a single key-on-run-key-off cycle which satisfies the enable criteria for a specific diagnostic function. Criteria may vary slightly to satisfy differing diagnostic functions. For this reason, the definition of trip may vary with the specific application. The Diagnostic Executive uses trip information in setting and erasing DTCs.

After engine has reached normal operating temperature, Diagnostic Executive checks if on-board diagnostic tests have been completed since last ignition cycle. Executive checks if tests have passed during current ignition cycle, and if fault(s) identified by diagnostic tests is currently active. Executive also checks if fault identified has been active during current ignition cycle and what operating conditions were present at the time of failure.

A malfunction will set one of 4 types of DTC

  1. Type A Turns the MIL on the first time an emission related failure occurs. The MIL may flash at a rate of once per second to alert the operator of potentially damaging levels of misfire, which could possibly destroy the catalytic converter. History DTC, Freeze Frame and Fail Record are stored, and Fail Records are updated each time current diagnostic test fails.
  2. Type B Will only turn MIL on if an emission related condition occurs during 2 consecutive drive cycles. Conditions such as incorrect fuel trim will be stored in the freeze-frame data until the fault is detected a second time. If the fault is not detected during 3 consecutive drive cycles, the MIL light will be turned off.
  3. Type C This is a non-emission related type DTC and will not activate the MIL. It will turn on a Service light or message on Driver Information Center (DIC), or other non-MIL service reminder light.
  4. Type D Is non-emission related, and will not turn on service light, but will store DTCs or Freeze frame data for present faults. Fail record is updated each time diagnostic test fails.

PRELIMINARY CHECK

Perform On-Board Diagnostic II system check. See ON-BOARD DIAGNOSTIC II SYSTEM CHECK . When it is established that OBD-II system is functioning properly, retrieve DTCs. See RETRIEVING CODES .

Hard Failures

Hard failures cause Malfunction Indicator Light (MIL) to glow and remain on until problem is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using diagnostic tests. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If a sensor fails, Powertrain Control Module (PCM) will use a substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, vehicle runs but driveability will not be optimum.

Intermittent Failures

Intermittent failures may cause MIL to flicker or glow and go out after intermittent fault goes away. However, corresponding DTC will be retained in PCM memory. If related fault does not reoccur within 3 consecutive drive cycles, related DTC will be erased from PCM memory. Intermittent failures may be caused by a sensor, connector or wiring related problems. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.

FREEZE-FRAME DATA

Engine operating conditions that cause MIL to illuminate are recorded in PCM memory. This record, called freeze frame data, is a snap shot of the driving conditions that are recorded on the PCM freeze frame buffer and is constantly updated with the most current information.

Freeze frame data can only be overwritten with misfire or fuel trim malfunction data. The data can only be erased by clearing associated history DTCs.

RETRIEVING CODES

Note. DTCs are retrieved using TECH II or other OBD-II compatible scan tool.

  1. DTC retrieval starts with OBD-II diagnostic system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . Also see WIRING DIAGRAMS article for circuits and terminals referenced in testing.
  2. Turn ignition on. MIL should come on and remain on steady when ignition is on and engine is not running. When engine is started, MIL should go off. If light remains on while engine is running, a DTC is stored.
  3. If light does not come on with ignition on and engine off, inspect MIL circuit before continuing. If MIL fails to operate, see «MALFUNCTION INDICATOR LIGHT INOPERATIVE»(ref-97343-S03831639392001050100000) .
  4. To retrieve codes, install scan tool. Follow scan tool manufacturer's instruction for DTC retrieval.

CLEARING CODES

  1. After repairs are performed, clear PCM memory of all stored codes. Ensure ignition is off. To clear codes, use diagnostic scan tool CLEAR DTCS or CLEAR INFO function. Follow instructions supplied by tool manufacturer when clearing DTCs.
  2. DTCs can also be cleared by disconnecting the PCM power source or negative battery cable for at least 30 seconds. However, if disconnecting battery, other memory functions (clock, radio, etc.) will need to be reset.

PCM PROGRAMMING PROCEDURE

If PCM requires replacement, PCM must be programmed using a Tech II or other OBD-II compatible scan tool. Some models may require additional equipment for reprogramming.

To reprogram PCM after it has been replaced, see EEPROM PROGRAMMING PROCEDURE under PROGRAMMING.

Rodeo 3.2L, Rodeo Sport 3.2L, Passport 3.2L & Trooper 3.5L

Note. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm impedance, unless stated otherwise in test procedure.

  1. Turn ignition on with engine off. Verify Malfunction Indicator Light (MIL) is on. If MIL is on, go to next step. If MIL is not on, go to «MALFUNCTION INDICATOR LIGHT INOPERATIVE»(ref-97343-S03831639392001050100000) .
  2. Verify REDUCED POWER LAMP (RPL) is on. If RPL is on, go to next step. If RPL is not on, go to «NO REDUCED POWER LAMP (RODEO, RODEO SPORT & PASSPORT)»(ref-97343-S06771229692001050100000) , or «NO REDUCED POWER LAMP (TROOPER)»(ref-97343-S11547041342001050100000) .
  3. Turn ignition off. Install TECH II scan tool. Follow manufacturer`s instructions for scan tool operation. Turn ignition on. If scan tool displays PCM data, go to next step. If scan tool does not display PCM data, verify scan tool is properly installed. If scan tool is properly installed, go to step 12 .
  4. Using scan tool, command MIL (CHECK ENGINE lamp) OFF. If MIL turns off, go to next step. If MIL does not turn off, go to «MIL ON STEADY»(ref-97343-S29627249122001050100000) .
  5. Using scan tool, command MIL (REDUCED POWER LAMP) OFF. If MIL (RPL) turns off, go to next step. If MIL (RPL) does not turn off, go to «REDUCED POWER LAMP ON STEADY (RODEO, RODEO SPORT & PASSPORT)»(ref-97343-S40211956472001050100000) or. «REDUCED POWER LAMP ON STEADY (TROOPER)»(ref-97343-S01136800292001050100000) .
  6. Using scan tool, check if any DTCs have been set. If any DTCs are set, go to next step. If no DTCs are set, go to step 11 .
  7. Check to see if any of the following DTCs are stored: P0562, P0563, P0601, P0602, P0604, P0606, P1625, P1635, P1639, P1640 or P1650. If any of the listed DTCs are present, go to appropriate diagnostic test procedure. If none of the listed DTCs are present, go to next step.
  8. Check to see if any of the following DTCs are stored: P1514, P1515, P1516, P1523, P1125, P1290, P1295 or P2299. If any of the listed DTCs are present, go to appropriate diagnostic test procedure. If none of the listed DTCs are present, go to next step.
  9. Check to see if two or more of the following DTCs are present: P0106, P0107, P0336, P0337, P0341, P0342, P0401, P0425, P1107, P1120, P1220, P1221, P1271, P1272, P1273, P1275, P1280, P1285, P1404, P1405, P1515, P1516, P1635 or P1639. If two or more of the listed DTCs are present, go to «MULTIPLE PCM INFORMATION SENSOR DTCS SET»(ref-97343-S19201127482001050100000) . If two or more of the listed DTCs are not present, go to next step.
  10. Start engine. If engine starts and continues to run, go back to step 6 . If engine will not run, go to ENGINE CRANKS BUT WILL NOT RUN under NO START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES article.
  11. Compare PCM data values displayed to typical engine scan data values. If values displayed are normal or close to typical values, OBD-II system check is complete. If driveability problem is still present, go to TROUBLE SHOOTING - NO CODES article. If values are not correct, go to SYSTEM & COMPONENT TESTING article.
  12. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on with engine off. Check for open or short in class 2 data circuit between Data Link Connector (DLC) terminal No. 2 and PCM Blue 80-pin connector terminal F58 (Orange/Black wire on Rodeo, Rodeo Sport and Passport, Orange/Green wire on Trooper). See WIRING DIAGRAMS article. Also check for open or short in ignition feed circuit between DLC terminal No. 16 and dash fuse box. Also check for open in ground circuit (Black wire) to DLC terminal No. 4. If any problems were found, repair as necessary and return to step 2 . If no problems were found, go to next step.
  13. Attempt to reprogram EEPROM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Programming PCM/EEPROM requires the use of a scan tool and special manufacturer equipment. Attempt to display PCM data on scan tool. If data is now displayed, return to step 2 . If data is not displayed, go to next step.
  14. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. After repair, recheck system operation.

Vehicross 3.5L

Note. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm impedance, unless stated otherwise in test procedure.

  1. Turn ignition on with engine off. Verify Malfunction Indicator Light (MIL) is on. If MIL is on, go to next step. If MIL is not on, go to «MALFUNCTION INDICATOR LIGHT INOPERATIVE»(ref-97343-S03831639392001050100000) .
  2. Turn ignition off. Install TECH II scan tool. Turn ignition on. If scan tool displays PCM data, go to next step. If scan tool does not display PCM data, verify scan tool is properly installed. If scan tool is properly installed, go to step 8 .
  3. Using scan tool, select MIL dash lamp control, command MIL OFF. If MIL turns off, go to next step. If MIL does not turn off, go to «MIL ON STEADY»(ref-97343-S29627249122001050100000) .
  4. Start engine. If engine starts and continues to run, go to next step. If engine will not run, go to ENGINE CRANKS BUT WILL NOT RUN under NO START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES article.
  5. Using scan tool, select "Display DTCs" and check if any DTCs have been set. If any DTCs are set, go to next step. If no DTCs are set, go to step 7 .
  6. If 2 or more of the following DTCs are stored, go to «MULTIPLE PCM INFORMATION SENSOR DTCS SET»(ref-97343-S19201127482001050100000) . If a single DTC is stored, go to appropriate DTC test under DIAGNOSTIC TESTS. P0107 P0108 P0113 P0118 P0122 P0123 P0712
  7. Compare PCM data values displayed to typical engine scan data values. See appropriate SCAN TOOL DATA VALUES table under PIN VOLTAGE (VALUE) TESTS in PIN VOLTAGE CHARTS article in ENGINE PERMANCE. If values displayed are normal or close to typical values, OBD-II system check is complete. If driveability problem is still present, go to TROUBLE SHOOTING - NO CODES article in ENGINE PERMANCE. If values are not correct, go to appropriate component test in SYSTEM & COMPONENT TESTING article.
  8. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on with engine off. Check for open or short in class 2 data circuit (Orange/Green wire) between Data Link Connector (DLC) terminal No. 2 and PCM 32-pin Red connector terminal B13. Also check for open or short in ignition feed circuit (Green/White wire) between DLC terminal No. 16 and fuse box. Also check for open in ground circuit (Black wire) to DLC terminal No. 4. If problem is found, repair as necessary and return to step 2 . If no problem is found, go to next step.
  9. Attempt to reprogram EEPROM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Programming PCM/EEPROM requires the use of a scan tool and special manufacturer equipment. Attempt to display PCM data on scan tool. If data is now displayed, return to step 2 . If data is not displayed, go to next step.
  10. Replace and reprogram PCM. After repair, return to step 2 .

SUMMARY

If no hard fault codes are present, driveability symptoms are present or intermittent codes are present, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

MALFUNCTION INDICATOR LIGHT INOPERATIVE

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Attempt to start engine. If engine does not start, go to step 6 . If engine starts, go to next step.
  3. Check METER (15-amp) fuse located in dash fuse box. If fuse is okay, go to next step. If fuse is blown, go to step 16 .
  4. Turn ignition on. Using test light connected to ground, probe ignition feed circuit at instrument cluster. If test light illuminates, go to next step. If test light does not illuminate, go to step 13 .
  5. Turn ignition off. Disconnect PCM harness connector(s). Connect a jumper wire between ground and Malfunction Indicator Light (MIL) control circuit at PCM harness connector. Turn ignition on. If MIL comes on, go to step 10 . If MIL does not come on, go to step 11 .
  6. Check ENGINE (15-amp) fuse and PCM (15-amp) fuse. If fuses are okay, go to next step. If fuses are blown, go to step 15 .
  7. Turn ignition off. Disconnect PCM harness connector(s). Turn ignition on. Using test light connected to ground, probe ignition feed circuits at PCM harness connectors. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
  8. Using test light connected to ground, probe battery feed circuit at PCM harness connector. If test light illuminates, go to next step. If the test light does not illuminate, go to step 14 .
  9. Check for faulty PCM ground connections. Repair as necessary. If connections are okay, go to next step.
  10. Check PCM harness connectors for damaged terminals. If any terminals are damaged, repair as necessary. If PCM harness connector terminals are okay, go to step 17 .
  11. Check for an open in MIL control circuit between PCM and MIL. Repair as necessary. If circuit is okay, go to step 18 .
  12. Substitute PCM main relay with a known-good relay. PCM main relay is located in fuse/relay box in engine compartment. Observe MIL. If MIL operates properly, replace PCM main relay. If MIL still does not operate, go to next step.
  13. Repair open in ignition feed circuit between PCM main relay and dash fuse box.
  14. Repair open in PCM battery feed circuit between PCM and fuse/relay box located in engine compartment.
  15. Repair short to ground in PCM ignition feed circuit or PCM battery feed circuit. See WIRING DIAGRAMS article. Replace fuse.
  16. Repair short to ground in ignition feed circuit between instrument cluster and dash fuse box. Replace fuse.
  17. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Verify proper system operation.
  18. Check MIL driver circuit for poor connection at instrument cluster connector. Repair as necessary. If no problem is found, diagnose problem in instrument cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.

MALFUNCTION INDICATOR LIGHT ON STEADY

  1. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. If Malfunction Indicator Light (MIL) comes on, go to next step. If MIL does not come on, go to step 5 .
  3. Turn ignition off. Disconnect instrument panel cluster connector. Check for short to ground in MIL control circuit between PCM harness connector and instrument panel cluster. Repair as necessary. Repeat OBD-II system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . If circuit is okay, go to next step.
  4. Replace instrument panel cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Repeat OBD-II system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .
  5. Turn ignition off. Reconnect PCM harness connectors. Turn ignition on. Reprogram EEPROM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Using scan tool, command MIL OFF. If MIL did not go off, go to next step. If MIL did go off, repeat OBD-II system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .
  6. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Repeat OBD-II system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .

NO REDUCED POWER LAMP (RODEO, RODEO SPORT & PASSPORT)

  1. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step 11 .
  3. Check MAIN (100-amp), B+1 (60-amp), B+2 (50-amp), METER (15-amp), ECM (15-amp) and ENGINE (15-amp) fuses. If none of the fuses were blown, go to next step. If any of them were blown, go to step 14 .
  4. Turn ignition off. Disconnect instrument cluster harness connector. Turn ignition on. Connect test light to ground and probe ignition feed circuit at instrument cluster harness connector. If test light is on, go to next step. If test light is not on, go to step 15 .
  5. Turn ignition off. Disconnect Multiplex Control Unit (MCU). Check for faulty lamp driver circuit between PCM and MCU. If a problem was found, go to step 16 . If no problems were found, go to next step.
  6. Reconnect instrument cluster connector. Connect fused jumper wire between ground and Reduced Power Lamp (RPL) driver circuit at MCU harness connector. Turn ignition on. If RPL comes on, go to next step. If RPL does not come on, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.
  7. Turn ignition off. With test light connected to ground, probe ignition feed circuit at MCU harness connector. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, go to step 17 .
  8. Turn ignition off. Disconnect PCM harness connectors. Check for faulty circuit between PCM and MCU harness connectors. If no problems were found, go to next step. If a problem was found, go to step 18 .
  9. Check MCU ground connection and circuit. If no problem was found, go to next step. If problem was found, go to step 19 .
  10. Check for damaged terminals at MCU. If no problem was found, go to next step. If problem was found, go to step 20 .
  11. Turn ignition on. With test light connected to ground, probe ignition feed circuit at PCM harness connector. If test light illuminates, go to next step. If test light did not illuminate, go to step 21 .
  12. Turn ignition off. Check PCM ground connection and circuit. If no problem was found, go to next step. If problem was found, go to step 23 .
  13. Check for damaged terminals at PCM. If problem was found, go to step 24 . If no problem was found, go to step 25 .
  14. Replace blown fuse. Retest system.
  15. Locate and repair open circuit in battery feed to instrument cluster. Retest system.
  16. Locate and repair open circuit between instrument cluster and MCU. Retest system.
  17. Locate and repair open circuit in battery feed to MCU. Retest system.
  18. Locate and repair open circuit between PCM and MCU. Retest system.
  19. Locate and repair faulty ground circuit for MCU. Retest system.
  20. Replace MCU. Retest system.
  21. Substitute known-good relay for PCM main relay. Retest system. If problem is still present, go to next step.
  22. Repair open ignition feed circuit. Retest system.
  23. Locate and repair faulty ground circuit for PCM. Retest system.
  24. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Retest system.
  25. Reconnect all harness connectors. Turn ignition on. Use scan tool to select RPL DASH LAMP CONTROL. Command RPL to turn ON. If RPL turned on, repairs are complete. If RPL did not turn on, go to next step.
  26. Turn ignition off. Disconnect PCM harness connectors. Check for faulty circuit between PCM and DLC. If problem was found, go to next step. If no problem was found, go back to step 24 .
  27. Locate and repair problem in circuit between PCM and DLC. Go back to step 25 .

NO REDUCED POWER LAMP (TROOPER)

  1. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step 6 .
  3. Check for blown METER (10-amp) fuse. If fuse is okay, go to next step. If fuse is blown, go to step 16 .
  4. Turn ignition on. With test light connected to ground, probe ignition feed circuit at instrument cluster harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 13 .
  5. Turn ignition off. Disconnect PCM harness connectors. Connect fused jumper wire between ground and RPL driver circuit at PCM harness connector. Turn ignition on. If RPL turns on, go to step 10 . If RPL does not turn on, go to step 11 .
  6. Check for blown ENGINE (15-amp) or PCM (15-amp) fuses. If either fuse is blown, go to next step. If either fuse is not blown, go to step 15 .
  7. Turn ignition on. With test light connected to ground, probe ignition feed circuit at PCM harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
  8. Probe battery feed circuit at PCM harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 14 .
  9. Check for faulty PCM ground connection. Repair as necessary. If no problem was found, go to next step.
  10. Check for damaged terminals at PCM. Repair as necessary. If no problem was found, go to step 17 .
  11. Check for open driver circuit between RPL and PCM. Repair as necessary. If no problem was found, go to step 18 .
  12. Substitute known-good relay for PCM main relay. Retest system. If problem is still present, go to next step.
  13. Repair open ignition feed circuit to instrument cluster. Retest system.
  14. Repair open battery feed circuit to PCM. Retest system.
  15. Locate and repair short to ground in PCM ignition feed or battery feed circuit. Retest system.
  16. Locate and repair short to ground in instrument cluster ignition feed circuit. Replace METER (10-amp) fuse and retest system.
  17. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Retest system.
  18. Check RPL driver circuit for poor connection at instrument cluster harness connector. Repair as necessary. If no problem was found, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.

REDUCED POWER LAMP ON STEADY (RODEO, RODEO SPORT & PASSPORT)

  1. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect Multiplex Control Unit (MCU). Turn ignition on. If Reduced Power Lamp (RPL) is on, go to next step. If RPL is off, go to step 4 .
  3. Turn ignition off. Disconnect instrument cluster harness connector. Check for short to ground on RPL driver circuit between MCU and instrument cluster. Repair as necessary. If no problem was found, go to next step.
  4. Replace MCU. Turn ignition on. Use scan tool output controls function, select RPL DASH LAMP CONTROL and command RPL to turn off. If RPL turned off, repair is complete. If RPL did not turn off, go to step next step.
  5. Turn ignition off. Disconnect PCM harness connectors. Check for faulty lamp driver circuit between PCM and MCU. If problem was found, go to next step. If problem was not found, go to step 7 .
  6. Locate and repair open in lamp driver circuit between PCM and MCU. Go to next step.
  7. Use scan tool to select RPL DASH LAMP CONTROL. Command RPL to turn off. If RPL turned off, repairs are complete. If RPL did not turn off, go to next step.
  8. Turn ignition off. Check for faulty circuit between PCM and DLC. If problem was found, go to next step. If no problem was found, go to step 10 .
  9. Locate and repair problem in circuit between PCM and DLC. Go back to step 7 .
  10. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .

REDUCED POWER LAMP ON STEADY (TROOPER)

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. If Reduced Power Lamp (RPL) is on, go to next step. If RPL is off, go to step 5 .
  3. Turn ignition off. Disconnect instrument cluster harness connector. Check for short to ground on RPL driver circuit between PCM and instrument cluster. Repair as necessary. Perform On-Board Diagnostic II (OBD-II) System Check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . If no problem was found, go to next step.
  4. Replace instrument cluster. Perform On-Board Diagnostic II (OBD-II) System Check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .
  5. Turn ignition off. Reconnect PCM harness connectors. Use scan tool to reprogram EEPROM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Select RPL DASH LAMP CONTROL. Command RPL to turn OFF. If RPL turned off, perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . If RPL did not turn off, go to next step.
  6. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .

Passport 3.2L, Rodeo 3.2L, Rodeo Sport 3.2L & Trooper 3.5L

  1. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM electrical connectors. Turn ignition on. Check for poor connections, opens or shorts in either 5-volt reference circuits for affected sensors. See WIRING DIAGRAMS article. If problem is found, go to next step. If circuits are okay, go to step 4 .
  3. Repair faulty circuit as necessary. Verify system is operating properly.
  4. Check for poor connections or open in ground circuits of affected sensors. See WIRING DIAGRAMS article. If problem is found, go to next step. If connections and circuits are okay, go to step 6 .
  5. Repair faulty circuit as necessary. Verify system is operating properly.
  6. Use scan tool to check for stored DTCs. If DTC P1635, P1639 or P1646 is stored, go to appropriate diagnostic test procedure under «DIAGNOSTIC TESTS»(ref-97343-S23284716092001050100000) . If none of the listed DTCs are stored, go to next step.
  7. Using DVOM, measure resistance of 5-volt supply circuit between following components: EGR Pintle Position Sensor (EGR-PS) and Fuel Tank Pressure (FTP) sensor. MAP sensor and FTP sensor. FTP sensor and PCM harness connector. If resistance is not as specified, go to next step. If resistance of each circuit is about zero ohms, go to step 9 .
  8. Locate and repair open in supply circuit of MAP, EGR and FTP sensors. See WIRING DIAGRAMS article. Retest system.
  9. Disconnect MAP, FTP and EGR sensor harness connectors. Measure resistance between each component's harness connector ground wire terminal and chassis ground. If resistance is about zero ohms on all circuits, go to step 11 . If resistance is not as specified, go to next step.
  10. Locate and repair fault in MAP, EGR or FTP ground circuit. See WIRING DIAGRAMS article.
  11. Using DVOM, measure resistance of 5-volt supply circuit between following components: Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor. CKP sensor and PCM harness connector. If resistance of each circuit is about zero ohms, go to step 13 . If resistance is not as specified, go to next step.
  12. Locate and repair open in 5-volt supply circuit. See WIRING DIAGRAMS article. Retest system.
  13. Disconnect CKP and CMP sensor harness connectors. Measure resistance between each sensor's harness connector ground wire terminal and chassis ground. If resistance is about zero ohms on all circuits, go to step 15 . If resistance is not as specified, go to next step.
  14. Locate and repair fault in CKP or CMP sensor ground circuit. See WIRING DIAGRAMS article.
  15. Use scan tool to check for any stored EGR, FTP, MAP, CKP, CMP, TPS or APS DTCs. If any listed DTCs are stored, go to appropriate diagnostic test procedure under «DIAGNOSTIC TESTS»(ref-97343-S23284716092001050100000) . If DTCs are not stored, go to next step.
  16. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Repeat OBD-II system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .
  1. Perform «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) . After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Check for poor connections, open or short in 5-volt reference circuit for affected sensors. See WIRING DIAGRAMS article. If problem is found, go to next step. If circuits are okay, go to step 4 .
  3. Repair as necessary. Verify system is operating properly.
  4. Check for poor connections or open in ground circuits of affected sensors. If problem is found, go to next step. If connections and circuits are okay, go to step 6 .
  5. Repair faulty ground circuits as necessary. Verify system is operating properly.
  6. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM connector. See WIRING DIAGRAMS article. If voltage is about zero volts, go to next step. If voltage is not about zero volts, go to step 12 .
  7. Using DVOM, check voltage between ground and MAP sensor signal circuit at PCM harness connector. If voltage is about zero volts, go to next step. If voltage is not about zero volts, go to step 15 .
  8. Using DVOM, check voltage between ground and TP sensor signal circuit at PCM harness connector. If voltage is about zero volts, go to next step. If voltage is not about zero volts, go to step 16 .
  9. Using DVOM, check voltage between ground and IAT sensor signal circuit at PCM harness connector. See WIRING DIAGRAMS article. If voltage is about zero volts, go to next step. If voltage is not about zero volts, go to step 17 .
  10. Using DVOM, check voltage between ground and ECT sensor signal circuit at PCM harness connector. If voltage is about zero volts, go to next step. If voltage is not about zero volts, go to step 18 .
  11. Disconnect EGR valve. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM harness connector. If voltage is about zero volts, go to step 13 . If voltage is not about zero volts, go to step 18 .
  12. Using DVOM, check voltage between ground and Transmission Fluid Temperature (TFT) sensor signal circuit at PCM harness connector. See WIRING DIAGRAMS article. If voltage is about zero volts, go to step 20 . If voltage is not about zero volts, go to step 19 . NOTE: TFT sensor may also be referred to as A/T oil temperature sensor.
  13. Replace EGR valve. Verify system is operating properly.
  14. Repair short circuit to voltage between PCM harness connector and MAP sensor. Retest system.
  15. Repair short circuit to voltage between PCM harness connector and TP sensor. Retest system.
  16. Repair short circuit to voltage between PCM harness connector and IAT sensor. See WIRING DIAGRAMS article. Retest system.
  17. Repair short circuit to voltage between PCM harness connector and ECT sensor. Retest system.
  18. Repair short circuit to voltage between PCM harness connector and EGR pintle position sensor. Retest system.
  19. Repair short circuit to voltage between PCM harness connector and sensor TFT sensor. See WIRING DIAGRAMS article. Retest system.
  20. Replace and reprogram PCM. See «EEPROM PROGRAMMING PROCEDURE»(ref-97343-S42360493802001050100000) under PROGRAMMING. Repeat OBD-II system check. See «ON-BOARD DIAGNOSTIC II SYSTEM CHECK»(ref-97343-S01178100682001050100000) .

EEPROM PROGRAMMING PROCEDURE

Note. Refer to latest Isuzu Technical Communication System (ITCS) information for reprogramming or flashing procedures. Programming PCM/EEPROM requires the use of a scan tool and special manufacturer equipment.

Connect TECH II scan tool to DLC and retrieve information from PCM. Ensure that battery is fully charged. Turn ignition on. Ensure that Vehicle Interface Module cable connection is securely connected to DLC. Follow scan tool instructions to program EEPROM using latest software available from ITCS. If PCM fails to program, recheck PCM connections. Ensure that most recent ITCS information is being used. Attempt to program PCM. If it still can not be programmed properly, replace PCM. Reprogram new PCM, then perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. Start engine and run for one minute. Use scan tool to check for any stored DTCs.

Code Enable Criteria

Following conditions must be met for DTC diagnostic test to run

  1. Ignition is on.
  2. Difference between TPS1 and TPS2 correlation of 6.5 or more percent within 125 milliseconds.

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