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Home >> Saturn >> 2003 >> Ion 1 Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> System Tests >> Mil Always On >> 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. Turn ignition switch to OFF position. Disconnect ECM harness connectors. Turn ignition switch to RUN position, engine off. Observe the MIL. Is the MIL illuminated? If yes, go to next step. If no, go to step  5.
  3. Check the MIL control circuit for a short to ground. Did you find and correct the condition? If yes, go to step  6. If no, go to next step.
  4. Replace IPC. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. After replacement, go to step  6.
  5. Replace ECM. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION - ION article. Perform ECM relearn procedure. See ENGINE CONTROL MODULE REPROGRAMMING  under PROGRAMMING. After repair, go to next step.
  6. Turn ignition switch to OFF position for 30 seconds. Start engine. Does the vehicle operate correctly without any unwanted MIL illumination, and without any stored DTCs? If yes, system is okay at this time. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
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