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:

    Customer Assistance Offices (U.S. and Canada)
    GMC encourages customers to call the toll-free number for assistance. However, if a customer wishes to write or e-mail GMC, the letter should be addressed to: United States GMC Customer Assistance ...

    Brake Fluid
    The brake master cylinder reservoir is filled with DOT 3 brake fluid. See Engine Compartment Overview on page 10‑6 for the location of the reservoir. There are only two reasons why the brake ...

    Storing a Radio Station as a Favorite
    Drivers are encouraged to set up their radio station favorites while the vehicle is in P (Park). Tune to favorite stations using the presets, favorites button, and steering wheel controls. See Steerin ...