For 1990-2009 cars only
Removal Procedure
- Open the rear compartment lid.
- Remove the forward rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement .
- Disconnect the cellular coaxial cable (2) from the OnStar® VCU by pulling upward on the spring loaded snap connector.
- Disconnect the electrical connector.
- Remove the VCU (6) by lifting the retainer tab (1).
- Remove the VCU (6).
- The old VCU must be returned for core credit.
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.
Installation Procedure
- Record the 11-digit ESN from the label on the new VCU module.
- Install the OnStar® VCU (6) into the module bracket assembly.
- Connect the electrical connector.
- Connect the cellular coaxial cable (2) to the VCU (6) until fully seated.
- Ensure the locking tab (1) is secure to the VCU.
- Install the forward rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement .
- Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .
- Close the rear compartment lid.
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.
