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 Oil Pressure Light
    WARNING Do not keep driving if the oil pressure is low. The engine can become so hot that it catches fire. Someone could be burned. Check the oil as soon as possible and have the vehicle serviced. ...

    Hill Start Assist (HSA)
    Non-hybrid vehicles with StabiliTrak have a Hill Start Assist (HSA) feature, which may be useful when the vehicle is stopped on a grade. This feature is designed to prevent the vehicle from rolling, ...

    Roof Rack System
    WARNING If something is carried on top of the vehicle that is longer or wider than the roof rack—like paneling, plywood, or a mattress—the wind can catch it while the vehicle is being driven. ...