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:

    Entering the Feature Settings Menu
    1. Turn the ignition on and place the vehicle in P (Park). To avoid excessive drain on the battery, it is recommended that the headlamps are turned off. 2. Press the customization button to enter th ...

    What to Use
    WARNING Adding only plain water or some other liquid to the cooling system can be dangerous. Plain water and other liquids, can boil before the proper coolant mixture will. The coolant warning syste ...

    Power Liftgate Operation
    On vehicles with a power liftgate, the vehicle must be in P (Park) to use the power feature. The taillamps flash when the power liftgate moves. Notice: If you open the liftgate without checking f ...