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:

    Antilock Brake System (ABS) Warning Light
    For vehicles with the Antilock Brake System (ABS), this light comes on briefly when the engine is started. If it does not, have the vehicle serviced by your dealer. If the system is working normall ...

    Engine Compartment Overview
    A. Radiator Pressure Cap. See Cooling System on page 10‑14. B. Engine Coolant Recovery Cap. See Cooling System on page 10‑14. C. Remote Negative (−) Terminal. See Jump Starting o ...

    Driving in Mud, Sand, Snow, or Ice
    Use a low gear when driving in mud – the deeper the mud, the lower the gear. Keep the vehicle moving to avoid getting stuck. Traction changes when driving on sand. On loose sand, such as on beaches ...