See also:

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 the v ...

Roadside Assistance Program
For U.S.-purchased vehicles, call 1-800-252-1112; (Text Telephone (TTY): 1-888-889-2438). For Canadian-purchased vehicles, call 1-800-268-6800. Service is available 24 hours a day, 365 days a year. ...

Head Restraint Adjustment
Do not drive until the head restraints for all occupants are installed and adjusted properly. To achieve a comfortable seating position, change the seatback recline angle as little as necessary while ...