Sierra 3500 4WD V8-6.0L VIN U (2004)
Global Positioning System Module: Service and Repair
COMMUNICATION INTERFACE MODULE REPLACEMENT
REMOVAL PROCEDURE
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 (STID) and the 11-digit electronic serial number (ESN), are used by the National Cellular Network and
Onstar(R) 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. Remove the instrument panel (I/P) top trim panel.
2. Disconnect the wire connectors (2) from the module.
3. Disconnect the coaxial cable (3) from the module.
4. Remove the nuts (2) retaining the module to the bracket.
5. Remove the module (3) from the vehicle.
INSTALLATION PROCEDURE
1. If replacing the VCIM, record the 10-digit STID number, and the 11-digit ESN number from the labels on the new module.