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:

    Highway Hypnosis
    Is there actually such a condition as highway hypnosis? Or is it just plain falling asleep at the wheel? Call it highway hypnosis, lack of awareness, or whatever. There is something about an eas ...

    Automatic Transmission Shift Lock Control Function Check
    WARNING When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured. 1. Before starting this check, be sure there is enough room aro ...

    Manual Locks
    From the outside, unlock the door using either the key or the RKE transmitter. From the inside, use the power door lock switches or manual lock knobs located at the top of the door panel near t ...