GM Service Manual Online
For 1990-2009 cars only

Pre-Removal Procedure

Important: It is necessary to record the remaining engine oil life. If the replacement module is not programmed with the remaining engine oil life, the engine oil life will default to 100%. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5000 km (3,000 mi) from the last engine oil change.

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.

If the engine control module (ECM) is replaced, the following procedures must be performed:

    Important: When replacing the ECM, the ECM must be reset prior to removal. Failure to perform this procedure will result in the inability to:

       • Test the ECM for warranty purposes.
       • Install the ECM into other vehicles.

  1. ECM reset procedure.
  2. ECM reprogramming - Refer to Service Programming System (SPS) Notice Service Programming System (SPS) Notice.
  3. Theft Deterrent programming - Refer to Theft Deterrent Control Module Programming and Setup Theft Deterrent Control Module Programming and Setup.

Removal Procedure

    Caution: Refer to Safety Glasses Caution in the Preface section.

    Notice: Always turn the ignition off when installing or removing the ECM connectors in order to prevent damage to the components.

  1. Turn the ignition OFF.
  2. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection Battery Negative Cable Disconnection and Connection.
  3. Remove the radiator air baffle and deflector. Refer to Radiator Air Upper Baffle and Deflector Replacement Radiator Air Upper Baffle and Deflector Replacement.

  4. Object Number: 1994665  Size: SH

    Important: Disconnect the rear electrical connector from the ECM first.

  5. Unlock the ECM electrical connector lock levers (1) and disconnect the ECM electrical connectors (2).

  6. Object Number: 1949890  Size: SH
  7. Remove the ECM (2) from the ECM housing by pushing both ECM retaining clips (1) outwards.

Installation Procedure


    Object Number: 1949890  Size: SH
  1. Install the ECM (2) to the ECM housing, make sure the ECM retaining clips (1) are located correctly.

  2. Object Number: 1994665  Size: SH
  3. Connect the ECM electrical connectors (2) and lock the connector lock levers (1) into place.
  4. Connect the battery negative cable to the battery. Refer to Battery Negative Cable Disconnection and Connection Battery Negative Cable Disconnection and Connection.
  5. Install the radiator air baffle and deflector. Refer to Radiator Air Upper Baffle and Deflector Replacement Radiator Air Upper Baffle and Deflector Replacement.
  6. Important: If the ECM is replaced it is required to update the remaining engine oil life. If the replacement module is not programmed with the remaining engine oil life, the engine oil life will default to 100%. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5000 km (3,000 mi) from the last engine oil change.

  7. Program the ECM. Refer to Engine Control Module Programming and Setup Engine Control Module Programming and Setup.
  8. If you encounter an ECM programming error, with a display message of "Starting Disabled, Remove Key" on the driver information centre, with a diagnostic test code (DTC) of P1631, perform the "10-Minute Relearn Procedure" found in Programming Theft Deterrent Control Module Programming and Setup. Refer to Theft Deterrent Control Module Programming and Setup Theft Deterrent Control Module Programming and Setup.
  9. Turn OFF the ignition for at least 5 seconds after the programming event is complete.
  10. Perform the throttle learn procedure. Refer to Throttle Learn Idle Learn.
  11. Use the scan tool to clear all DTCs.