GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Chevy C Cab/Chassis HD (GMT 400) 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Powertrain Control Module Replacement

Service of the powertrain control module (PCM) should normally consist of either replacement of the PCM or electrically erasable programmable read only memory (EEPROM) programming. If the diagnostic procedures call for the PCM to be replaced, the PCM should be inspected first to see if the correct part is being used. If the correct part is being used, remove the faulty PCM and install the new service PCM.

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: The replacement PCM must be programmed.

Removal Procedure

    Object Number: 731235 Size: SH

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

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

  1. Disconnect the PCM harness connectors (4) from the PCM (1) by loosening the PCM harness connector bolts (3).
  2. Release the PCM retaining clip (2) from the PCM (1).

    3. Object Number: 731237 Size: SH
  3. Slide the PCM (1) out of the PCM mounting bracket (3).
  4. Remove the PCM (1) from the engine compartment.

Installation Procedure

    Object Number: 731237 Size: SH
  1. Install the PCM (1) to the PCM mounting bracket (3) ensuring that the PCM is engaged in the mounting tabs.
  2. Secure the PCM retaining clip (2) to the PCM.

    3. Object Number: 731235 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.

  3. Connect the PCM harness connectors (4) to the PCM (1).

    4. Tighten
    Tighten the PCM harness connector bolts (3) to 8 N·m (70 lb in).

  4. If a new PCM is being installed, program the PCM. Refer to Powertrain Control Module Programming .