Webthe vehicle communication interface module (vcim) is part of the onstar system and interacts with several other electronic control devices in the vehicle. Take their vehicle to their dealer for the system. Webwhat you'll need is a gmlan generation 2 based vcim (onstar version 7. 0 and above made after 2006), an antenna module foot from another theta platform. Web€€€€•€ the vehicle communication interface module (vcim) has a specific set of unique numbers that tie the module to each vehicle. By kconn001 » february 4th, 2012, 12:00 am. Can anyone…