TTY Users

OnStar has the ability to communicate to the deaf, hard-of-hearing, or speech-impaired customers while in the vehicle. The available dealer-installed TTY system can provide in-vehicle access to all of the OnStar services, except Virtual Advisor and OnStar Turn-by-Turn Navigation.

    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 vehic ...

    Shoulder Belt Height Adjuster
    The vehicle has a shoulder belt height adjuster for the driver and right front passenger seating positions. Adjust the height so the shoulder portion of the belt is on the shoulder and not fallin ...

    Cooling System
    If the vehicle has the Duramax® Diesel engine, see the Duramax® Diesel Supplement for more information. The cooling system allows the engine to maintain the correct working temperature. 5.3 L En ...