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:

    Antilock Brake System (ABS) Warning Light
    The ABS warning light comes on briefly when the ignition key is turned to ON/RUN. This is normal. If the light does not come on then, have it fixed so it will be ready to warn you if there is a pro ...

    Exterior Lighting
    The exterior lamps control is located on the instrument panel, to the left of the steering wheel. : Turns the automatic light control on or off. AUTO: Automatic operation of the headlamps at norm ...

    Compass Variance (Zone) Procedure
    1. Do not set the compass zone when the vehicle is moving. Only set it when the vehicle is in P (Park). Press the vehicle information button until PRESS TO CHANGE COMPASS ZONE displays. Or, if the v ...