Preliminary Procedures

1. Remove the rear shelf trim. Refer to Rear Window Shelf Trim Panel Replacement.
2. 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 (STID) and the 11-digit electronic serial number (ESN), 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.

1

Vehicle Communication Module Bolt

Caution: Refer to Fastener Caution in the Preface section.

Tip
When replacing the VCIM, record the 11-digit ESN and 10-digit STID number from the label on the new VCIM.

Tighten
9 N·m (80 lb in)

2

Vehicle Communication Module Assembly

Tip
After replacing the VCIM, you must reconfigure the OnStar® system. 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 key pad will NOT reset this version of the OnStar® system. This action will cause a DTC to set.