Removal Procedure

WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: The vehicle communication interface module (VCIM) has a specific set of unique numbers that tie the module to each vehicle. 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 of the vehicle, you must never exchange these parts with those of another vehicle.

Remove the right rear compartment trim. Refer to Compartment Trim Panel Replacement - Rear in Body Rear End.
Remove the nuts (2) securing the OnStar® module (1) to the vehicle body.

Fig 1: Identifying Communication Interface Module Nuts
Courtesy of GENERAL MOTORS CORP.
Disconnect all the electrical connectors from the module.

Fig 2: Identifying Communication Interface Module Connectors
Courtesy of GENERAL MOTORS CORP.
Remove the module from the vehicle.