GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 725614  Size: SH

    Important: The vehicle communication unit (VCU) has a specific set of unique numbers that tie the module to each vehicle. These numbers, the 10-digit station identification and the 11-digit electronic serial number, are used by the National Cellular Network and OnStar® to identify the specific vehicle. Because these numbers are tied to the vehicle identification number of the vehicle, you must never exchange these parts with those of another vehicle.

  1. Remove the clip-on strap securing the VCU to the bracket.

  2. Object Number: 725713  Size: SH
  3. Disconnect the electrical connectors.
  4. Disconnect the cell antenna coaxial cable from the VCU.
  5. The old VCU must be returned for core credit.

Installation Procedure

  1. Record the 11-digit ESN number from the label on the new part.

  2. Object Number: 725614  Size: SH
  3. Install the VCU to the bracket using the clip-on strap.
  4. Reconnect the cell antenna coaxial cable to the VCU.

  5. Object Number: 725713  Size: SH
  6. Reconnect the electrical connectors.

  7. Object Number: 725615  Size: SH
  8. Secure the VCU bracket to the instrument panel metal brace.
  9. Important: After replacing the VCU, you must reconfigure the OnStar® system. Failure to reconfigure the system will result in an additional customer visit for repair.

  10. Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .
  11. Return the old VCU for core credit.