GM Service Manual Online
For 1990-2009 cars only

Notice: 

   • Turn the ignition OFF when installing or removing the control module connectors and disconnecting or reconnecting the power to the control module (battery cable, powertrain control module (PCM)/engine control module (ECM)/transaxle control module (TCM) pigtail, control module fuse, jumper cables, etc.) in order to prevent internal control module damage.
   • Control module damage may result when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control module, using battery booster cables, or when charging the vehicle battery.
   • In order to prevent any possible electrostatic discharge damage to the control module, do no touch the connector pins or the soldered components on the circuit board.
   • Remove any debris from around the control module connector surfaces before servicing the control module. Inspect the control module connector gaskets when diagnosing or replacing the control module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the control module.
   • The replacement control module must be programmed.

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.

Removal Procedure

  1. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.

  2. Object Number: 1285259  Size: SH
  3. Turn the ignition OFF.
  4. Important: Ensure that there is no main relay circuit voltage (ECM Fuse).

  5. Use a DVOM in order to measure the main relay circuit voltage at the engine control module (ECM) fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  6. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection .
  7. Remove the ECM fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  8. Remove the TCM/IPC fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  9. Remove the ECM/TCM fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  10. Unlock the body side (outboard) ECM electrical connector.
  11. 8.1. Depress the ECM electrical connector lever lock (1).
    8.2. Simultaneously rotate the ECM connector clamp lever and depress the lock slide (2).

    Notice: In order to prevent any possible electrostatic discharge damage to the ECM, do not touch the connector pins.


    Object Number: 1394047  Size: SH
  12. Remove the body side (outboard) ECM connector.

  13. Object Number: 1394046  Size: SH
  14. Unlock and remove the engine side (inboard) ECM connector (2).

  15. Object Number: 1394045  Size: SH
  16. Remove the ECM redundant ground wire and bolt from the ECM.

  17. Object Number: 1394049  Size: SH
  18. Remove the ECM bolts.
  19. Remove the ECM.

  20. Object Number: 1394048  Size: SH
  21. If necessary, perform the following steps:
  22. 14.1. Remove the ECM bracket bolts.
    14.2. Remove the ECM bracket.

Installation Procedure


    Object Number: 1394048  Size: SH
  1. Install the ECM bracket, as necessary.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the ECM bracket bolts.
  4. Tighten
    Tighten the ECM bracket bolts to 10 N·m (89 lb in).


    Object Number: 1394049  Size: SH

    Notice: In order to prevent any possible electrostatic discharge damage to the ECM, do not touch the connector pins.

  5. Install the ECM.
  6. Install the ECM bolts.
  7. Tighten
    Tighten the ECM bolts to 10 N·m (89 lb in).


    Object Number: 1394045  Size: SH
  8. Install the ECM redundant ground and bolt to the ECM.
  9. Tighten
    Tighten the ECM redundant ground wire bolt to 5 N·m (44 lb in).


    Object Number: 1394046  Size: SH
  10. Install the engine side (inboard) ECM connector (2).

  11. Object Number: 1394047  Size: SH
  12. Install the body side (outboard) ECM connector.
  13. Install the ECM/TCM fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  14. Install the TCM/IPC fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  15. Install the ECM fuse in the underhood fuse block. Refer to Electrical Center Identification Views .
  16. Connect the battery negative cable to the battery. Refer to Battery Negative Cable Disconnection and Connection .
  17. Program the ECM. Refer to Control Module References .
  18. Turn OFF the ignition for at least 5 seconds after the programming event is complete.