See also:

Check Gages Warning Light
The check gages light will come on briefly when you are starting the engine. If the light comes on and stays on while you are driving, check your coolant temperature and engine oil pressure ...

Compass Zone
Your dealer/retailer will set the correct zone for your location. If the zone is not set to your location or you drive out of the area, the variance needs to be changed to the appropriate zone. ...

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if ...