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 ...

Engine Oil Messages
CHANGE ENGINE OIL SOON This message displays when the engine oil needs to be changed. When you change the engine oil, be sure to reset the Oil Life System. See Engine Oil Life System  and Driv ...

Engine Power Messages
ENGINE POWER IS REDUCED This message displays when the vehicle's engine power is reduced. Reduced engine power can affect the vehicle's ability to accelerate. If this message is on, but there is no ...