GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy P12 Chassis 🢒 Engine 🢒 Engine Controls - 7.4L 🢒 Powertrain Control Module Replacement

Important: Do not substitute a PCM from another vehicle for diagnosis.

Removal Procedure

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.

Important: The ignition should always be OFF when installing or removing the PCM connectors.

  1. Open the front access panel and remove the engine cover from the interior.

    2. Object Number: 215293 Size: SH
  2. Remove the PCM harness connectors (5).
  3. Remove the PCM retainer bolt/screw (1) and nut from the top of the radiator support.
  4. Remove the PCM bracket (3) with the PCM (4) from the vehicle.
  5. Remove the PCM from the bracket.

Installation Procedure

    Object Number: 215293 Size: SH
  1. Install the PCM (4) to the bracket (3).
  2. Position the PCM bracket and retainer (2) to the PCM bracket assembly (7) on top of the radiator support.

    3. 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. Install the PCM retainer bolt/screw (1) and nut.

    4. Tighten
    Tighten the PCM retainer nut to 8.0 N·m (6 lb ft).

  4. Install the PCM harness connectors (5).
  5. Program the EEPROM if a new PCM is being installed.

EEPROM Programming

Setup

  1. Ensure that the following conditions have been met:
    2. • The battery is fully charged.
    • The ignition is ON.
    • The scan tool cable connection at the DLC is secure.
  2. Program the PCM using the latest software matching the vehicle. Refer to the Techline terminal/equipment users instructions.
  3. If the PCM fails to program, proceed as follows:
    4. • Ensure that all PCM connections are OK.
    • Check the Techline terminal/equipment for the latest software version.
    • Attempt to program the PCM. Replace the PCM if the PCM still cannot be programmed properly.

Functional Check
  1. Perform the On-Board Diagnostic System Check.
  2. Start the engine and run for 1 minute.
  3. Scan for DTCs using the scan tool.