OnStar (R) Vehicle Interface Unit (VIU) Replacement

REMOVAL PROCEDURE




1. Remove the vehicle communication unit (VCU) from the vehicle interface unit (VIU).
2. Remove the nuts from the VIU/VCU bracket.
3. Remove the VIU from the inner Wheel Housing.




4. Disconnect the global positioning system (GPS) antenna cable from the VIU.

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




5. Disconnect the red 32-way connector from the VIU.




6. Disconnect the blue 32-way connector from the VIU.




7. Remove the mounting screws from the VIU.
8. Remove the VIU from the VIU/VCU bracket.

INSTALLATION PROCEDURE




1. Position the VIU to the VIU/VCU bracket.

NOTE: Refer to Fastener Notice in Service Precautions.

2. Install the mounting bracket screws to the VIU.

Tighten
Tighten the OnStar(R) mounting bracket screws to the VIU to 2 N.m (18 lb in).




3. Connect the global positioning system GPS antenna cable to the VIU.

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




4. Connect the red 32-way connector to the VIU.




5. Connect the blue 32-way connector to the VIU.




6. Position the VIU to the inner Wheel Housing.
7. Install the OnStar(R) mounting bracket nuts to the VIU/VCU bracket.

Tighten
Tighten the OnStar(R) mounting bracket nuts to the VIU/VCU bracket to 3 N.m (27 lb in).

8. Install the vehicle communication unit VCU.
9. Reprogram the VIU whenever you replace the VIU or when the power to the VIU has been disconnected. Refer to Vehicle Interface Unit (VIU)/Vehicle Communication Unit (VCU) Reprogramming. Programming and Relearning