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Home >> Saturn >> 2003 >> LW200 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> 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 SATURN "L" SERIES article. If no, go to next step.
  3. Turn ignition off. Remove fuse that supplies voltage to the MIL. Disconnect the 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  8.
  4. Turn ignition off. 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  7. If no, go to next step.
  5. Check the MIL control circuit for an open or high resistance. Did you find and correct a condition? If yes, go to step  11. If no, go to next step.
  6. Check for an intermittent and for a poor connection at the IPC. Did you find and correct the condition? If yes, go to step  11. If no, go to step  9.
  7. Check for an intermittent and for a poor connection at PCM. Did you find and correct the condition? If yes, go to step  11. If no, go to step  10.
  8. Repair short to voltage in the MIL control circuit. After repairs, go to step  11.
  9. Replace IPC. Go to appropriate INSTRUMENT PANEL article in ACCESSORIES & EQUIPMENT. After replacement, go to step  11.
  10. Replace PCM. See POWERTRAIN CONTROL MODULE in REMOVAL & INSTALLATION - SATURN "L" SERIES article. Perform PCM relearn procedure. See PCM REPROGRAMMING  under PROGRAMMING. After repair, go to next step.
  11. Remove all test equipment. Connect any disconnected components or any disconnected fuses. Turn ignition switch to OFF position for 30 seconds. Start 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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