OnStar Vehicle Interface Unit (VCU) Replacement

ONSTAR VEHICLE INTERFACE UNIT (VIU) REPLACEMENT

IMPORTANT: Both the vehicle interface unit (VIU) and the vehicle communication unit (VCU) have a specific set of unique numbers that tie the module to the vehicle where the module resides. 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 (VIN) of the vehicle, do NOT exchange these parts with those of another vehicle.

Removal Procedure




1. Remove the rear compartment trim.
2. Disconnect the electrical connectors on the VIU module.
3. Remove the global position sensor (GPS) antenna cable (2) from the VIU module.
4. Remove the VIU module from the bracket assembly.
5. The old VIU must be returned for core credit.

Installation Procedure
1. Record the 10-digit STID number from the label on the new module.




2. Install the VIU module onto the bracket assembly.
3. Reconnect the electrical connectors.
4. Connect the GPS antenna cable (2) to the VIU.
5. 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.

6. Install a scan tool. Use the ID information menu to access the new STID number.
7. 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.
8. Press the blue OnStar(R) button to connect to the OnStar(R) call center.
8.1. Tell the advisor that this vehicle has received a new VIU.
8.2. Ask the advisor to add the new STID to update the customer's account.
8.3. Follow any additional instructions from the OnStar(R) advisor.
8.4. Ask the advisor to activate the OnStar(R) personal calling feature, if available.
9. Install the rear compartment trim.