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Home >> Cadillac >> 2005 >> STS 4.6 A, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 4.6L (LH2) - Introduction >> Repair Instructions >> Engine Control Module (ECM) Replacement >> Removal Procedure
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Removal Procedure

NOTE: Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.
    IMPORTANT: It is necessary to record the remaining engine oil life. If the replacement module is not programed with the remaining engine oil life, the engine oil life will default to 100 percent. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5 000 km (3,000 mi) from the last engine oil change.
    IMPORTANT: It is necessary to record the remaining automatic transmission fluid life. If the replacement module is not programed with the remaining automatic transmission fluid life, the automatic transmission fluid life will default to 100 percent. If the replacement module is not programmed with the remaining automatic transmission fluid life, the automatic transmission fluid will need to be changed at 83 000 km (50,000 mi) from the last automatic transmission fluid change.
  1. Using a scan tool, retrieve the percentage of remaining engine oil and the remaining automatic transmission fluid life. Record the remaining engine oil and the remaining automatic transmission fluid life.
  2. Turn OFF the ignition.
  3. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical.
  4. Fig 1: View Of Front Air Deflector And Push Pin retainers
    GM699902Courtesy of GENERAL MOTORS CORP.
  5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  6. Remove the front air deflector. Refer to Air Deflector Replacement - Front in Body Front End.
  7. Fig 2: View Of ECM
    GM1269407Courtesy of GENERAL MOTORS CORP.
  8. Disconnect the engine control module (ECM) electrical connectors (1).
  9. Remove the ECM mounting nuts (2).
  10. Remove the ECM from the vehicle.