GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Cavalier (CNG) 🢒 Engine 🢒 Engine Controls - 2.2L (LN2) 🢒 Engine Control Unit Replacement

Removal Procedure

    Object Number: 384176 Size: SH

    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.

  1. Disconnect the negative battery cable.
  2. Remove the Front Bumper Fascia. Refer to Front Bumper Fascia Replacement in Bumpers in the J Platform Service Manual.
  3. Remove the ECU relay bracket bolt and the ECU relay bracket.

    4. Object Number: 384177 Size: SH
  4. Remove the ECU.
  5. Disconnect the electrical connectors from the ECU.

    6. Perform the following step only if ECU Mounting Bracket removal is desired.


    Object Number: 384178 Size: SH
  6. Remove the nuts from the ECU bracket studs and remove the bracket.

Installation Procedure

    Object Number: 384178 Size: SH

    Important: Perform this step only if the ECU Mounting Bracket was previously removed.

  1. Install the ECU mounting bracket to the mounting studs using the stud nuts.

    2. Tighten
    Tighten the mounting stud nuts to 10 N·m (89 lb in).


    Object Number: 384177 Size: SH
  2. Connect the electrical connectors to the ECU.
  3. Install the ECU.

    4. Object Number: 384176 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.

  4. Install the ECU relay bracket.

    5. Tighten
    Tighten the ECU relay bracket bolt to 10 N·m (89 lb in).

  5. Install the Front Bumper Fascia. Refer to Front Bumper Fascia Replacement in Bumpers in the J Platform Service Manual.

    6. Important: The AF ECU must be programmed (flashed) before attempting to start the vehicle.

  6. Connect the negative battery cable.

    7. Tighten
    Tighten the bolt to 15 N·m (11 lb ft).