See also:

OnStar®
If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. See OnStar Overview. ...

Driving on Grades
Reduce speed and shift to a lower gear before starting down a long or steep downgrade. If the transmission is not shifted down, the brakes might get hot and no longer work well. Vehicles can tow ...

Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during severe operating conditions. See Engine Overheating. ...