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Home >> Buick >> 1996 >> Century Custom >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Engine Testing - 2.2L >> On-Board Diagnostic (OBD) System Check >> A-2, Mil On Steady
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A-2, Mil On Steady

  1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  . After performing OBD system check, go to next step.
  2. Turn ignition on with engine off. MIL should illuminate. If MIL does not illuminate, go to A-1, MIL INOPERATIVE  . If MIL illuminates, go to next step.
  3. Install Tech 1 scan tool. Using scan tool, select MISC. TESTS/ENGINE OUTPUT/MIL function, and command MIL on and off. If MIL turn on and off when commanded, go to step 8). If MIL does not turn on and off when commanded, go to next step.
  4. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on with engine off. If MIL does not illuminate, go to step 7). If MIL illuminates, go to next step.
  5. Check MIL control circuit (Brown/White wire) for short to ground. See Figure . Repair as necessary. After repairs, go to step 8). If circuit is okay, go to next step.
  6. Replace Instrument Panel Cluster (IPC). After replacing IPC, go to step 8).
  7. Replace PCM. After replacing PCM, go to next step.
  8. Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and runs, go to next step. If engine does not start or starts and dies, go to step 1).
  9. Warm engine to normal operating temperature. Check if any DTC(s) are set. If DTC(s) are set, diagnose affected DTC. See TESTS W/CODES article.
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