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:

    Lamps
    Properly working headlamps, taillamps, and brake lamps are important to see and be seen on the road. • Signs that the headlamps need attention include dimming, failure to light, cracking, or damage ...

    If a Tire Goes Flat
    It is unusual for a tire to blow out while driving, especially if the tires are maintained properly. See Tires on page 10‑37. If air goes out of a tire, it is much more likely to leak out slowly ...

    Tachometer
    The tachometer displays the engine speed in revolutions per minute (rpm). ...