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:

    Front Fog Lamp Light
    For vehicles with front fog lamps, this light comes on when the front fog lamps are in use. The light goes out when the front fog lamps are turned off. See Front Fog Lamps  for more inform ...

    Window Messages
    OPEN, THEN CLOSE DRIVER WINDOW This message is displayed when the window needs to be reprogrammed. If the vehicle's battery has been recharged or disconnected, you will need to reprogram eac ...

    Tire Chains
    WARNING: If your vehicle has P235/55R17, or P245/50R18 size tires, do not use tire chains. There is not enough clearance. Tire chains used on a vehicle without the proper amount of clearance c ...