Fig 1: Communication Interface Module Battery

Courtesy of GENERAL MOTORS CORP.

Callout	Component Name
Preliminary Procedure: Remove the right rear seat. Refer to Rear Seat Replacement .
1	Communication Interface Module Battery Bolt (Qty: 2) CAUTION: Refer to Fastener Caution . Tighten: 10 N.m (89 lb in)
2	Communication Interface Module Battery Assembly Procedure: Disconnect the electrical connectors. Tip: 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. Replacement of the back-up battery (BUB) does not require reconfiguration of the VCIM. If a trouble code is indicated before the battery is replaced, the DTC must be cleared following the installation of the new battery. The OnStar® system does not need to be reconfigured unless the VCIM is replaced. When the VCIM is replaced, the OnStar® system must be reconfigured. Failure to reconfigure the system will result in an additional customer visit for repair. In addition, pressing and holding the white dot button on the keypad will NOT reset this version of the OnStar® system. This action will cause a DTC to set.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Communication Interface Module Battery Replacement