GM Service Manual Online
For 1990-2009 cars only

Powertrain control module (PCM) service should normally consist of either PCM replacement or EEPROM programming. If the diagnostic procedures require PCM replacement, check the PCM first to see if the correct part is being used.

Important: In order to prevent internal PCM damage, the ignition must be OFF when you disconnect or reconnect the power to the PCM. For example, disconnect the power when you work with the following components:

    • A battery cable
    • The PCM pigtail
    • The PCM fuse
    • The jumper cables

Important: When you diagnose or replace the PCM, remove any debris from the PCM connector surfaces before servicing the PCM module connector gaskets. Ensure that the gaskets are installed correctly. The gaskets prevent intrusion into the PCM.

Important: The replacement PCM MUST be programmed.

Removal Procedure

    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%. 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.

  1. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
  2. Remove the wheelhouse filler panel. Refer to Wheelhouse Filler Replacement in Body Front End.
  3. Remove the throttle actuator control (TAC) module. Refer to Electronic Throttle Actuator Control Module Replacement .

  4. Object Number: 519848  Size: SH
  5. Disconnect the powertrain control module (PCM) electrical harness connectors.
  6. Loosen but do not remove the PCM rear retaining fastener. Use the rear retaining fastener as an anchor for the outer bracket.
  7. Remove the front retaining fastener from the PCM.
  8. Reposition the PCM outer bracket.

  9. Object Number: 519845  Size: SH
  10. Remove the PCM from the bracket and the vehicle.

Installation Procedure


    Object Number: 519845  Size: SH
  1. Install the PCM to the PCM rear bracket.
  2. Position the PCM front bracket.
  3. Notice: Refer to Fastener Notice in the Preface section.

  4. Install the PCM front retaining fasteners.
  5. Tighten
    Tighten the PCM retaining fasteners to 2.0 N·m (17 lb in).


    Object Number: 519848  Size: SH
  6. Connect the electrical connectors to the PCM.
  7. Tighten
    Tighten the PCM electrical connectors to 8 N·m (70 lb in).

  8. Install the TAC module. Refer to Electronic Throttle Actuator Control Module Replacement .
  9. Install the wheelhouse filler panel. Refer to Wheelhouse Filler Replacement in Body Front End.
  10. If a new PCM is being installed, program the PCM. Refer to Service Programming System (SPS) .