OnStar Services

See also:

Fuel E85 (85% Ethanol)
If the vehicle has the 3.9L V6 engine (VIN Code M), you can use either unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85). See Fuel. In all other engines, use only the unleaded ...

Engine Oil Life System
The engine oil life system calculates engine oil life based on vehicle use and displays the CHANGE ENGINE OIL SOON message when it is time to change the engine oil and filter. The oil life sy ...

Automatic Operation
AUTO (Automatic): When automatic operation is active, the system will control the inside temperature, the air delivery mode, and the fan speed. Use the steps below to place the entire system in ...