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 vehicle is equipped with the Tire Pressure Monitoring System. If a diagnostics check is needed between e-mails, push OnStar Additional Information, and an Advisor can run a check.

    See also:

    Setting Cruise Control
    If the cruise button is on when not in use, it could get bumped and go into cruise when not desired. Keep the cruise control switch off when cruise is not being used. The cruise control light on the ...

    Maintenance Replacement Parts
    Replacement parts identified below by name, part number, or specification can be obtained from your dealer. If your vehicle has a diesel engine, see the Duramax diesel supplement for more informa ...

    What to Use
    Read the manufacturer's instructions before refilling the windshield washer fluid. If operating the vehicle in an area where the temperature may fall below freezing, use a fluid that has suffi ...