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:

    If You Cannot See the HUD Image When the Ignition Is On
    • Is anything covering the HUD lens? • Is the HUD dimmer setting bright enough? • Is the HUD image adjusted to the proper height? • Are you wearing polarized sunglasses? • Still no HUD i ...

    Compass Messages
    CAL This message is displayed when the compass needs to be calibrated. See Compass on page 5‑5. – – – Three dashes will be displayed if the compass needs service. See your dealer fo ...

    Engine Air Cleaner/Filter
    If the vehicle has a diesel engine, see “Pickup Models” under “Engine Air Cleaner/Filter” in the Duramax® Diesel Supplement for the correct inspection and replacement procedures. See Engine ...