Vehicle Communication Unit/Vehicle Interface Unit (ONSTAR®)

After replacement of Vehicle Communication Unit (VCU), Vehicle Interface Unit (VIU) or Vehicle Communication Interface Module (VCIM), OnStar® system must be reprogrammed. Call OnStar® call center and follow operator instructions. Be prepared to give operator Electronic Serial Number (ESN) of VCU (2.6)/VCIM (F1) and/or Station ID (STID) number of VIU (2.6)/VCIM (F1).