GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Notice: In order to prevent internal damage to the PCM, the ignition must be OFF when disconnecting or reconnecting the PCM connector.

Service should normally consist of either replacement of the PCM or electronically erasable programmable read only memory (EEPROM) re-programming.

If the diagnostic procedures call for the PCM to be replaced, the PCM should be inspected first in order to verify the PCM is the correct part. DTC P0602 indicates the EEPROM programming has malfunctioned. When DTC P0602 is set, re-program the EEPROM.

    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. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Remove the left closeout/insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages, and Console.

  4. Object Number: 791323  Size: SH

    Notice: Do not touch the PCM connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage. Do not remove the integrated circuit boards from the carrier.

  5. Push down on the locking tab (1) and pull up on the release lever (2) and disconnect the PCM harness connectors.

  6. Object Number: 791324  Size: SH
  7. Depress the PCM retaining tab (1).
  8. Slide the PCM up and out from the PCM bracket.

Installation Procedure

Remove the new PCM from the packaging and inspect the service number to verify the number is the same number, or an updated number, as the faulty PCM.


    Object Number: 791324  Size: SH
  1. Slide the PCM into the PCM bracket. The retaining tab (1) will lock in place.

  2. Object Number: 791323  Size: SH

    Notice: Do not touch the PCM connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage. Do not remove the integrated circuit boards from the carrier.

  3. Install the PCM harness connectors and lock down the release levers (2).
  4. Install the left closeout/insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages, and Console.
  5. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  6. Important: : The replacement PCM must be reprogrammed and the crankshaft position (CKP) system variation learn procedure must be performed.

  7. Program the PCM. Refer to Service Programming System (SPS) in Programming.