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Home >> Buick >> 2018 >> Enclave Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 19 (Cellular System, Entertainment System, And Navigation System) >> Description and Operation >> OnStar Description and Operation (Z49) >> Vehicle Communication Interface Module
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Vehicle Communication Interface Module

WARNING: This page is about a different car, the 2017 GMC Acadia Limited, 2017 Chevrolet Traverse, and 2017 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.

The vehicle communication interface module is a cellular device that allows the user to communicate data and voice signals over the national cellular network. Power is provided by a dedicated, fused B+ circuit. Ground is provided through the vehicle wiring harness attached to the module. The ignition state is determined by the vehicle communication interface module through serial data messaging.

Dedicated circuits are used to connect the vehicle communication interface module to a microphone, the button assembly, and to command the status LED. The vehicle communication interface module communicates with the rest of the vehicle over the serial data bus.

The module houses 2 technology systems, one to process GPS data, and another for cellular information. The cellular system connects the OnStar® system to the cellular carrier's communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular antenna and cellular antenna coax. GPS satellites orbiting earth are constantly transmitting signals of their current location. The OnStar® system uses the GPS signals to provide location on demand.

The module also has the capability of activating the horn, initiating door lock/unlock, slowing down stolen vehicle gradually, or activating the exterior lamps using the serial data circuits. These functions can be commanded by the OnStar® Call Center per a customer request.