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:

    Automatic Dimming Rearview Mirrorwith Compass
    Your vehicle may have an automatic-dimming rearview mirror with a compass. (On/Off): This is the on/off button for the automatic dimming feature and compass. ...

    Compass Calibration
    Press and hold the on/off button to activate the compass calibration mode. CAL will be displayed in the compass window on the mirror. The compass can be calibrated by driving the vehicle in circ ...

    Hitches
    It is important to have the correct hitch equipment. Crosswinds, large trucks going by and rough roads are a few reasons why the right hitch is needed. Here are some rules to follow: • The rea ...