OnStar® Module Reprogramming
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Cadillac Escalade EXT. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
Follow the instruction set for the part that you are replacing. Both the Vehicle Interface Unit (VIU) and Vehicle Communication Unit (VCU) have a specific set of unique numbers that tie the module to the vehicle it resides in. These numbers, the 10 digit Station Identification and 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, these parts should NOT be exchanged with those of another vehicle. Failure to perform these steps will prevent the OnStar® features from functioning and will result in a customer return for repair.