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:

    Services Not Included in Roadside Assistance
    • Impound towing caused by violation of any laws. • Legal fines. • Mounting, dismounting, or changing of snow tires, chains, or other traction devices. • Towing or services for vehicl ...

    Battery Voltage
    This display, available on some vehicles, shows the current battery voltage. If the voltage is in the normal range, the value will display. For example, the display may read Battery Voltage 1 ...

    Engine Drive Belt Routing
    2.4L L4 Engine Belt removal and installation requires special tools. See your dealer for service. 3.6L V6 Engine ...