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Home >> Suzuki >> 2002 >> XL-7 Plus >> Repair and Diagnosis >> External Pages >> Different car >> Section 6 (Engine Controls - Self-Diagnostics) >> Malfunction Indicator Lights >> No Malfunction Indicator Light (Check Engine Light) >> Diagnostic Procedure
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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.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. 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 C-10 METER GAUGE (10-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 for "S" models at instrument cluster harness connector I-9 terminal No. 5 (Violet wire) or all other models at harness connector I-10 terminal No. 4 (Violet wire). See WIRING DIAGRAMS article. For further aid, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. If test light illuminates, go to next step. If test light does not illuminate, go to step  13.
  5. Turn ignition off. Disconnect PCM Red 80-pin harness connector E-22. PCM is located at right rear of engine compartment. Connect a jumper wire between ground and PCM harness connector E-21 terminal No. 11 (Violet wire). Turn ignition on. If MIL illuminates, go to step  10. If MIL does not illuminate, go to step  11.
  6. Check C-8 ENGINE (15-amp) and FL-3 ECM (30-amp) fuses. If fuses are okay, go to next step. If fuses are blown, go to step  15.
  7. 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. Using test light connected to ground, probe PCM ignition feed circuits at PCM harness connector E-22 terminal No. 32 (Red/Blue wire) and PCM harness connector E-21 terminal No. 75 (Red/Blue wire). If test light illuminates, leave test light connected to ground and go to next step. If test light does not illuminate, go to step  12.
  8. Probe PCM battery feed circuit at PCM harness connector E-21 terminals No. 20 and 57 (both wires are White). If test light illuminates, go to next step. If the test light does not illuminate, go to step  14.
  9. Check for poor, loose or corroded PCM ground connections. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair, observe MIL. If MIL operates properly, testing is complete. If no problem is found, go to next step.
  10. Check for poor, loose, corroded or damaged terminals in PCM harness connectors. If problem is found, repair as necessary. After repair, observe MIL. If MIL operates properly, testing is complete. If no problem is found, go to step  17.
  11. Check for an open in Violet wire (MIL control circuit) between PCM and MIL. If problem is found, repair as necessary. After repair, observe MIL. If MIL operates properly, testing is complete. If no problem is found, go to step  18.
    12. NOTE: Horn relay also located in fuse/relay box is like PCM relay. Verify horn relay by pressing horn button to ensure horn is operational. If horn relay tests good, install relay to PCM relay position for test purposes.
  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 Red/Blue wire (ignition feed circuit) between PCM main relay and PCM. After repair, observe MIL. If MIL operates properly, testing is complete.
  14. Repair open in White wire (battery feed circuit) between FL-3 ECM (30-amp) fuse and PCM. After repair, observe MIL. If MIL operates properly, testing is complete.
  15. Locate and repair short to ground in PCM ignition feed circuit or PCM battery feed circuit. See WIRING DIAGRAMS article. Replace fuse. Observe MIL. If MIL operates properly, testing is complete.
  16. Located and repair short to ground in ignition feed circuit between instrument cluster and dash fuse box. Replace fuse. Observe MIL. If MIL operates properly, testing is complete.
  17. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. Use scan tool to clear DTC and verify repair.
  18. Check MIL driver circuit for poor connection at instrument cluster connector. If problem is found, repair as necessary. If no problem is found, diagnose problem in instrument cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.
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