Important: Never swap OnStar® vehicle integration units (VIU), or the vehicle communication units (VCU) from other vehicles. Transfer of OnStar® components from other vehicles should NOT be done. Each OnStar® component has a unique identification number. The VIU has a 10-digit specific station identification (STID) and the VCU has a 11-digit specific electronic serial number (ESN). These identification numbers are used by the National Cellular Telephone Network and OnStar® systems, and are stored in the General Motors vehicle history files by VIN.

1. Open the rear compartment lid.
2. Remove the forward rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement .
3. Disconnect the OnStar® global positioning satellite (GPS) antenna coaxial cable (4) from the OnStar® VIU (5).
4. Disconnect the 2 electrical connectors.
5. Remove the VIU (5) by lifting the retainer tabs (3) upward.
6. Remove the VIU (5) from the vehicle.
7. The old VIU must be returned for core credit.

1. Record the 10-digit STID number from the label on the VIU module.



2. Install the OnStar® vehicle interface unit (VIU) (5) into the module bracket assembly.

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.

3. Connect the 2 electrical connectors.

Tighten
Apply 0.2 N·m (2 lb in) of torque, or less, to the thumb screw electrical connectors.

4. Connect the OnStar® GPS antenna coaxial cable (4) to the VIU (5) until fully seated.
5. Ensure the locking tabs (3) are secure to the VIU.
6. Install the forward rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement .
7. Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .

The 10-digit STID number recorded will be needed by the OnStar® Dealer Support line.

8. Close the rear compartment lid.