ONSTAR(R) Module Reprogramming: Notes
CAUTION:
DO NOT swap OnStar(R) Vehicle Integration Unit (VIU) or Vehicle Communication Unit (VCU) from other vehicles. Each OnStar(R) component has a unique identification number. VIU has a specific Station Identification (STID) and VCU has a specific Electronic Serial Number (ESN). These identification numbers are used by the National Cellular Telephone Network and OnStar(R) systems, and are stored in the General Motors vehicle history files by VIN.
NOTE:
Follow instructions for component being replaced in order listed. Failure to perform these steps will prevent OnStar(R) features from functioning and will result in a customer return for repair.