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Home >> Pontiac >> 2003 >> Sunfire Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics - 2.2L >> System Tests >> Mil Inoperative >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Verify whether the instrument cluster is operational. If the Instrument Panel (IP) is completely inoperative, see DIAGNOSTIC SYSTEM CHECK - INSTRUMENT CLUSTER in appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Command the MIL ON and OFF, using scan tool. Does the MIL turn ON and OFF when commanded using a scan tool? If yes, go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE - GASOLINE article. If no, go to next step.
  3. Inspect the fuse that supplies battery positive voltage to the MIL. Is the fuse open? If yes, go to step  10. If no, go to next step.
  4. Turn ignition switch to OFF position. Remove the fuse that supplies voltage to the MIL. Disconnect the Powertrain Control Module (PCM) harness connectors. Turn ignition switch to RUN position, engine OFF. Measure voltage between the MIL control circuit in the PCM harness connector and a good ground. Is the voltage less than 0.3 volt? If yes, go to next step. If no, go to step  11.
  5. Turn ignition switch to OFF position. Install the fuse that supplies voltage to the MIL. Turn ignition switch to RUN position, engine OFF. Connect a 3-amp fused jumper wire between the MIL control circuit in the PCM harness connector and a good ground. Is the MIL illuminated? If yes, go to step  9. If no, go to next step.
  6. Turn ignition switch to OFF position. Remove the Instrument Panel Cluster (IPC). Go to appropriate INSTRUMENT PANEL article in ACCESSORIES & EQUIPMENT. Probe the MIL battery positive voltage circuit of the IPC harness connector using a test light connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step  12.
  7. Check the MIL control circuit for an open or high resistance. Did you find and correct a condition? If yes, go to step  15. If no, go to next step.
  8. Check for an intermittent and for a poor connection at the IPC. Did you find and correct the condition? If yes, go to step  15. If no, go to step  13.
  9. Check for an intermittent and for a poor connection at the PCM. Did you find and correct the condition? If yes, go to step  15. If no, go to step  14.
  10. Repair the short to ground in the battery positive voltage circuit. After repair, go to step  15.
  11. Repair the short to voltage in the MIL control circuit. After repair, go to step  15.
  12. Repair the open in the MIL battery positive voltage circuit. After repair, go to step  15.
  13. Replace the IPC. Go to appropriate INSTRUMENT PANEL article in ACCESSORIES & EQUIPMENT. After repair, go to step  15.
  14. Replace PCM. See appropriate REMOVAL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE REPROGRAMMING  under PROGRAMMING. After repair, go to next step.
  15. Remove all test equipment. Connect any disconnected components or any disconnected fuses. Turn ignition switch to OFF position for 30 seconds. Start the engine and operate the vehicle performance, and driveability. Observe the MIL, the vehicle performance, and the driveability. Does the vehicle operate correctly, without any MIL illumination and without any stored DTCs? If yes, system is okay at this time. If no, diagnose appropriate DTC. Go to DIAGNOSTIC TROUBLE CODE DEFINITIONS .
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