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:

    Collision Damage Repair (U.S. and Canada)
    If the vehicle is involved in a collision and it is damaged, have the damage repaired by a qualified technician using the proper equipment and quality replacement parts. Poorly performed col ...

    Lane Departure Warning (LDW) Light
    For vehicles with the lane departure warning system, this light briefly comes on green, while starting the vehicle, to indicate that it is working. If it does not, have the vehicle servic ...

    Headlamps
    The headlamp wiring is protected by four fuses. An electrical overload will cause a lamp to go on and off. If this happens, have your headlamp wiring checked right away. ...