Diagnostic Procedure
WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.
- Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
- Turn ignition off. Disconnect PCM 80-pin harness connectors E-21 (Blue) and E-22 (Red). PCM is located at right rear of engine compartment. Turn ignition on. If MIL illuminates, go to next step. If MIL does not illuminate, go to step 5.
- Turn ignition off. Disconnect instrument panel cluster (I-9 30-pin "S" models; I-10 22-pin all others) harness connector. Check for short to ground in Violet wire (MIL control circuit) between PCM harness connector and instrument panel cluster. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair, repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
- Replace instrument panel cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Turn ignition off. Reconnect PCM harness connectors. Turn ignition on. Reprogram EEPROM. See EEPROM PROGRAMMING PROCEDURE under POWERTRAIN CONTROL MODULE. Using scan tool, select MISCELLANEOUS TESTS, and command MIL OFF. If MIL did turn off, repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. If MIL did not turn off, go to next step.
- Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT under POWERTRAIN CONTROL MODULE. After repair, repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.