GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Classic 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Powertrain Control Module Replacement

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.

Removal Procedure

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.

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

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

    4. Object Number: 791324 Size: SH
  4. Depress the PCM retaining tab (1).
  5. 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.

  2. Install the PCM harness connectors and lock down the release levers (2).
  3. Install the left closeout/insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages, and Console.
  4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

    5. Important: : The replacement PCM must be reprogrammed and the crankshaft position (CKP) system variation learn procedure must be performed.

  5. Program the PCM. Refer to Control Module References in Computing/Integrating Systems.