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:

    Lane Departure Warning (LDW) Light
    For vehicles with the lane departure warning system, this light is located on the center of the instrument panel. This light briefly comes on green while starting the vehicle. If it does not, h ...

    Running the Vehicle While Parked
    It is better not to park with the engine running. But if you ever have to, here are some things to know. WARNING Idling a vehicle in an enclosed area with poor ventilation is dangerous. Engine exhau ...

    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 ...