Removal Procedure

Fig 1: View Of Vehicle Communication Interface Module

Courtesy of GENERAL MOTORS CORP.

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 rear shelf trim. Refer to Trim Panel Replacement - Rear Window Shelf .
Remove the interface module from the bracket by pulling back on the bracket tabs.
Disconnect the electrical harnesses and the antenna cable.