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:

    Engine Coolant Temperature Gage
    This gage shows the engine coolant temperature. If the gage pointer moves into the red area, the engine coolant has overheated. If you have been operating your vehicle under normal driving c ...

    Driving on Grades
    Notice: Do not tow on steep continuous grades exceeding 6 miles (9.6 km). Extended, higher than normal engine and transmission temperatures may result and damage the vehicle. Frequent stops ar ...

    Driving with a Trailer
    CAUTION: If you have a rear-most window open and you pull a trailer with your vehicle, carbon monoxide (CO) could come into your vehicle. You cannot see or smell CO. It can cause unconsciousn ...