Removal Procedure
- Open the rear compartment.
- Remove the cover from the OnStar® vehicle communication unit (VCU) by depressing the retainer tabs.
- Remove the cellular coaxial cable from the VCU by pulling off.
- Remove the screws from the DB-25 connector.
- Remove the DB-25 connector from the VCU.
- Release the retainer strap from the VCU using a small flat-bladed tool.
- Remove the VCU from the rear compartment.
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 number from the label on the new part.
- Install the cellular coaxial cable to the VCU pressing into place until fully seated.
- Install the DB-25 connector to the VCU pressing into place until fully seated.
- Hand tighten the screws to the DB-25 connector.
- Position the (VCU) to the top of the vehicle interface unit (VIU).
- Install the retainer strap to the VCU pressing into place until fully seated.
- Install the cover to the VCU bay pressing the cover into place until fully seated.
- Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .
- Return the old VCU for core credit.
Notice: In order to avoid damage to the circuit board, do NOT over-tighten the thumb screws. Using your fingers, apply only a light pressure.
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.
