LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saturn >> 2003 >> L300 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> System Test >> Malfunction Indicator Light Inoperative >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Malfunction Indicator Light Inoperative: Procedure

  1. Did you perform the Diagnostic System Check-Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Verify whether the Instrument Panel Cluster (IPC) is operational. If IPC is completely inoperative, see appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Command the MIL ON and OFF with a scan tool. Does the MIL turn ON and OFF when commanded with a scan tool? If yes, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM. If no, go to next step.
  3. Inspect the fuse that supplies ignition voltage to the IPC. Is the fuse open? If yes, go to step  10. If no, go to next step.
  4. Turn ignition OFF. Remove the fuse that supplies voltage to the IPC. Disconnect the ECM. Turn ignition ON, with engine OFF. Measure the voltage between the MIL control circuit at the ECM harness connector and a good ground. Is the voltage less than 0.3 V? If yes, go to next step. If no, go to step  11.
  5. Turn ignition OFF. Install the fuse that supplies voltage to the IPC. Turn ignition ON, with engine OFF. Connect a 3-amp fused jumper wire between the MIL control circuit at the ECM 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 OFF. Remove IPC. See appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Turn ignition ON. Probe the ignition voltage circuit of the IPC harness connector with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step  12.
  7. Test 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. Test for an intermittent and/or poor connections at the IPC. Did you find and correct the condition? If yes, go to step  15. If no, go to step  13.
  9. Test for an intermittent and/or poor connections at the ECM. 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 ignition voltage circuit. Did you complete the repair? If yes, go to step  15.
  11. Repair the short to voltage in the MIL control circuit. Did you complete the repair? If yes, go to step  15.
  12. Repair the open in the ignition voltage circuit. Did you complete the repair? If yes, go to step  15.
  13. Replace the IPC. See appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Did you complete the replacement? If yes, go to step  15.
  14. Replace the ECM. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION - 3.0L SATURN "L" SERIES article. Did you complete the replacement? If yes, go to next step.
  15. Turn OFF the ignition for 30 seconds. Does the vehicle operate correctly, without any MIL illumination and without any stored DTCs? If yes, system is okay. If no, see DIAGNOSTIC TROUBLE CODE DEFINITIONS .
scientia non olet · About LEMON Manuals