OnStar (R) Vehicle Communication Unit (VCU) Replacement

REMOVAL PROCEDURE




1. Open the rear compartment.
2. Remove the cover from the OnStar(R) vehicle communication unit (VCU) by depressing the retainer tabs.




3. Remove the cellular coaxial cable from the VCU by pulling off.




4. Remove the screws from the DB-25 connector.




5. Remove the the DB-25 connector from the VCU.




6. Release the retainer strap from the VCU using a small flat-bladed tool.
7. Remove the VCU from the rear compartment.

INSTALLATION PROCEDURE




1. Install the cellular coaxial cable to the VCU pressing into place until fully seated.




2. Install the the DB-25 connector to the VCU pressing into place until fully seated.

NOTE: Refer to Avoid Circuit Board Damage Notice in Service Precautions.




3. Hand tighten the screws to the DB-5 connector.




4. Position the (VCU) to the top of the vehicle interface unit (VIU).
5. Install the retainer strap to the VCU pressing into place until fully seated.




6. Install the cover to the VCU bay pressing the cover into place until fully seated.
7. Reprogram the VCU module whenever you replace the VCU module or when the power to the VCU module has been disconnected. Refer to Vehicle Interface Unit (VIU)/Vehicle Communication Unit (VCU) Reprogramming.
8. Close the rear compartment.