GM Service Manual Online
For 1990-2009 cars only

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

Service of the PCM should normally consist of either replacement of the PCM or EEPROM re-programming.

If the diagnostic procedures call for the PCM to be replaced, the PCM should be checked first to see if it is the correct part. DTC P0601 indicates the EEPROM programming has malfunctioned. When DTC P0601 is obtained, re-program the EEPROM.

The ignition should be OFF for at least 10 seconds before disconnecting power to the PCM so the IAC valve has time to move to the engine OFF position.

Removal Procedure

Important: Turn OFF the ignition to prevent internal PCM damage when the following are being performed:

   • The battery cables are removed and connected.
   • The PCM connectors are removed and connected
   • The PCM fuses are replaced
   • If jumper cables are used to start the vehicle
The ignition should be OFF for at least 10 seconds before disconnecting the power to the PCM so the IAC valve has time to move to the correct position.

    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. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  3. Disconnect the negative battery cable.
  4. Remove the left sound insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gauges, and Console.

  5. Object Number: 72295  Size: SH
  6. Loosen the PCM connectors screws (1).

  7. Object Number: 325922  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.

  8. Disconnect the PCM connectors.

  9. Object Number: 325927  Size: SH
  10. Open the PCM bracket latch.

  11. Object Number: 325924  Size: SH
  12. Slide the PCM from the PCM bracket.

Installation Procedure

Remove the new PCM from the packaging and verify the service number is the same number as the malfunctioning PCM or an updated number.


    Object Number: 325924  Size: SH
  1. Slide the PCM into the PCM bracket until retainer locks the PCM into position.

  2. Object Number: 325926  Size: SH
  3. Close the PCM bracket latch.
  4. 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.


    Object Number: 325922  Size: SH
  5. Install the PCM electrical connectors.

  6. Object Number: 72295  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  7. Tighten the PCM electrical connector screws (1).
  8. Tighten
    Tighten the screws (1) to 8 N·m (71 lb in).

  9. Install the left sound insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gauges, and Console.
  10. Connect the negative battery cable.
  11. Reprogram the PCM. Refer to Powertrain Control Module Programming and perform the crankshaft position (CKP) system variation learn procedure. Refer to Crankshaft Position System Variation Learn .