Important: Never swap OnStar® vehicle integration units (VIU) or 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 specific station identification (STID) and the VCU has a 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 dash trim bezel. Refer to Instrument Panel Cluster Trim Plate Bezel Replacement .
2. Remove the garnish molding on the windshield pillar. Refer to Windshield Pillar Garnish Molding Replacement .
3. Remove the dash trim pad. Refer to Instrument Panel Upper Trim Pad Replacement .



4. Remove the 2 screws (3) securing the VCU bracket (2) to the instrument panel (I/P) metal brace (2).



5. Disconnect the electrical connectors (1).



6. Disconnect the cell antenna coaxial cable (1) from the VCU (2).
7. Remove the VCU from the bracket.
8. The old VCU must be returned for core credit.

1. Record the 11-digit ESN number from the label on the new part.



2. Install the VCU to the bracket (1).



3. Reconnect the cell antenna coaxial cable (1) to the VCU (2).



4. Reconnect the electrical connectors (2).

Notice: Refer to Fastener Notice in the Preface section.




5. Install the screws.

Tighten
Tighten the screws to 9 N·m (80 lb in).

Install the 2 screws (3) securing the VCU bracket (1) to the I/P metal brace (2).

6. Install the dash trim pad. Refer to Instrument Panel Upper Trim Pad Replacement .
7. Install the garnish molding on the windshield pillar. Refer to Windshield Pillar Garnish Molding Replacement .
8. Install the dash trim bezel. Refer to Instrument Panel Cluster Trim Plate Bezel Replacement .
9. Reconfigure the Onstar® system. Refer to OnStar Reconfiguration .

The ESN number will be needed by the Onstar® advisor.