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. Remove the rear compartment trim. Refer to Rear Compartment Trim Panel Replacement .
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.

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. Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .

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

6. Install the rear compartment trim. Refer to Rear Compartment Trim Panel Replacement .