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:

    System Identification
    If the vehicle has the tire sealant and compressor kit shown above, see the operating instructions that follow. If the vehicle has the tire sealant and compressor kit shown above, follo ...

    Antilock Brake System (ABS) Warning Light
    The Antilock Brake System (ABS) light comes on briefly when the engine is started. If the light does not come on, have the vehicle serviced by your dealer. If the ABS light comes on and stays on w ...

    Leaving After Parking on a Hill
    1. Apply and hold the brake pedal while you: 1.1. Start the engine. 1.2. Shift into a gear. 1.3. Release the parking brake. 2. Let up on the brake pedal. 3. Drive slowly until the trailer is clea ...