Circuit/System Description
WARNING: This page is about a different car, the 2008 Saturn Outlook, 2008 GMC Acadia, and 2008 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna housed in the quad band radio antenna receives these GPS signals and provides the data to the vehicle communication integration module VCIM to be processed.