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:

    Tire Pressure
    Tires need the correct amount of air pressure to operate effectively. Notice: Neither tire underinflation nor overinflation is good. Underinflated tires, or tires that do not have enough air, can re ...

    Instrument Panel Illumination Control
    This control is located on the instrument panel, to the left of the steering column. (Instrument Panel Brightness): Turn clockwise or counterclockwise to brighten or dim the lights. ...

    Engine Coolant Temperature Warning Light
    The engine coolant temperature warning light comes on briefly when the vehicle is started. If it does not, have the vehicle serviced by your dealer. If the system is working normally, the indicator ...