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 ...

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 ...

Ending a Call
Turn the Menu knob to select Hang Up, then press SELECT. ...