See also:

How OnStar Service Works
Automatic Crash Response, Emergency Services, Crisis Assist, Stolen Vehicle Assistance, Vehicle Diagnostics, Remote Door Unlock, Roadside Assistance, Turn-by-Turn Navigation, and Hands-Free Callin ...

Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can be obtained from your dealer. If your vehicle has a diesel engine, see the Duramax diesel supplement for more informa ...

XM™ Satellite Radio Service
XM Satellite Radio Service gives digital radio reception from coast to coast in the 48 contiguous United States, and in Canada. Just as with FM, tall buildings or hills can interfere with satellite ra ...