For 1990-2009 cars

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.

### Removal Procedure

1. Remove the windshield garnish molding. Refer to Windshield Pillar Garnish Molding Replacement .
2. Remove the upper trim pad. Refer to Instrument Panel Upper Trim Pad Replacement .
3. Disconnect the red 32-way electrical connectors and the blue 32-way electrical connector.
4. Disconnect the global position system (GPS) cables (1) from the VIU.

Important: Do NOT remove the VIU/VCU bolts from the bracket.

5. Loosen the 4 bolts and release the hook tab by rotating the module upwards in order to remove the VIU from the bracket.
6. 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. Install the VIU to the bracket by rotating the VIU downwards into the hook tab.
3. Connect the GPS cables (1) to the VIU.
4. Connect the red 32-way electrical connectors and the blue 32-way electrical connector.

Notice: Refer to Fastener Notice in the Preface section.

5. Install the bolt (2) which secures the VIU bracket to the instrument panel brace.

Tighten
Tighten the bolt to 10 N·m (89 lb in).

6. Install the upper trim pad. Refer to Instrument Panel Upper Trim Pad Replacement .
7. Install the windshield garnish molding. Refer to Windshield Pillar Garnish Molding Replacement .
8. Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .

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