Onstar Vehicle Interface Unit (Viu) Replacement

ONSTAR VEHICLE INTERFACE UNIT (VIU) REPLACEMENT

REMOVAL PROCEDURE
1. Remove the VCU from the VIU.

IMPORTANT: The vehicle interface unit (VIU) 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(R) 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.




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.




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.
9. The old VIU must be returned for core credit.

INSTALLATION PROCEDURE
1. Record the 10-digit STID number from the label on the VIU module.
2. Position the VIU to the VIU/VCU bracket.




3. Install the OnStar(R) mounting bracket screws to the VIU.

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten
Tighten the screws to 2 N.m (18 lb in).




4. Connect the GPS antenna cable to the VIU.




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

NOTE: In order to avoid damage to the circuit board, do NOT over-tighten the thumb screws. Using your fingers, apply only a light pressure.




6. Connect the blue 32-way connector to the VIU.
7. Position the VIU to the inner wheel housing.




8. Install the OnStar(R) mounting bracket nuts to the VIU/VCU bracket.

Tighten
Tighten the bracket nuts to 3 N.m (27 lb in).

9. Install the vehicle communication unit VCU.

10. Press and hold the white dot button until the OnStar(R) status LED turns from green to red, and back again to green.

IMPORTANT: After replacing the VIU, you must reconfigure the OnStar(R) system. Failure to reconfigure the system will result in an additional customer visit for repair.

11. Install a scan tool. Use the ID information menu to access the new STID number.
12. Move the vehicle to an open area that is away from tall buildings and with a clear view of unobstructed sky. Allow the vehicle to run for 10 minutes.
13. Press the blue OnStar(R) button to connect to the OnStar(R) call center.
13.1. Tell the advisor that this vehicle has received a new VIU.
13.2. Ask the advisor to add the new STID to update the customer's account.
13.3. Follow any additional instructions from the OnStar(R) advisor.
13.4. Ask the advisor to activate the OnStar(R) personal calling feature, if available.
14. Return the old VIU for core credit.