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:

    Headlamp High/Low-Beam Changer
    (Headlamp High/Low-Beam Changer): Push the turn signal/lane change lever away from you and release, to turn the high beams on. To return to low beams, push the lever again or pull it toward y ...

    When the Light Is On Steady
    This indicates that one or more of the tires are significantly underinflated. A Driver Information Center (DIC) tire pressure message may also display. See Vehicle Messages  for more informati ...

    Interior Mirrors
    Automatic Dimming Rearview Mirror The vehicle may have an automatic dimming inside rearview mirror. Automatic dimming reduces the glare from the headlamps of the vehicle behind you. The dimming fe ...