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:

    All-Wheel Drive
    Vehicles with this feature always send engine power to all four wheels. It is fully automatic, and adjusts itself as needed for road conditions. When using a compact spare tire on an AWD vehicle, t ...

    Power Lumbar
    Power Lumbar To adjust the power lumbar support, if equipped: • On vehicles with two-way lumbar, press and hold the top or bottom of the control to increase or decrease lumbar support. • On v ...

    Manual Operation of Power Liftgate
    To change the liftgate to manual operation, turn the mode switch to the OFF position. With the power liftgate disabled and all of the doors unlocked, the liftgate can be manually opened and closed. ...