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:

    Compass Variance (Zone) Procedure
    1. Do not set the compass zone when the vehicle is moving. Only set it when the vehicle is in P (Park). Press the vehicle information button until PRESS TO CHANGE COMPASS ZONE displays. Or, if the v ...

    Speedometer
    The speedometer shows how fast the vehicle is moving in either kilometers per hour (km/h) or miles per hour (mph). The speedometer cannot be reset. ...

    Tow/Haul Mode Light
    For vehicles with the Tow/Haul Mode feature, this light comes on when the Tow/Haul Mode has been activated. For more information, see Tow/Haul Mode on page 9‑42. ...