DTC U1500: INTER-DEVICE DEDICATED BUS MALFUNCTION GMC Yukon Denali

Note. Never swap OnStar® Vehicle Integration Units (VIU) or Vehicle Communication Units (VCU) from other vehicles. Transfer of OnStar® components from other vehicles should not be done. Each OnStar® component has a unique identification number. The VIU has a specific Station Identification (STID) and the VCU has a specific Electronic Serial Number (ESN). These identification numbers are used by the National Cellular Telephone Network and OnStar® systems, and are stored in the General Motors vehicle history files by VIN.