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:

    Fog Lamps
    Use the fog lamps for better vision in foggy or misty conditions. The fog lamps button is on the exterior lamps control to the left of the steering column. (Fog Lamps): Press the exterior lamps but ...

    Using Cruise Control on Hills
    How well the cruise control will work on hills depends upon the vehicle speed, load, and the steepness of the hills. When going up steep hills, you might have to step on the accelerator pedal to maint ...

    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 ...