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Home >> Buick >> 2001 >> Regal LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.8L >> System Tests >> Mil Always On >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing powertrain diagnostic system check, go to next step.
  2. Turn ignition on, engine off. If MIL turns off when ignition is turned on, go to step  5. If MIL does turn off when ignition is turned on, go to next step.
  3. Turn ignition off. Disconnect PCM. Turn ignition on, engine off. Observe MIL. If MIL is on, go to next step. If MIL is off, go to step  7.
  4. Remove IPC. Check Brown/White wire between PCM and IPC for a short to ground. If problem was found, repair as necessary. After repairs, go to step  8. If problem was not found, go to step  6.
  5. Repair short to voltage in Brown/White wire between IPC and PCM. After repairs, go to step  8.
  6. Replace IPC. After repairs, go to step  8.
  7. Replace PCM. After repairs, go to next step.
  8. Operate system to verify repair.
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