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:

    Tire Pressure Monitor
    This vehicle may have a Tire Pressure Monitor System (TPMS). The Tire Pressure Monitor alerts you when a significant reduction in pressure occurs in one or more of the vehicle’s tires ...

    Recommended Fuel
    Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when ...

    Finding a Category (CAT) Station (XM™ Satellite Radio Service Only)
    CAT (Category): The radio may have the CAT button feature. To select and find a desired category: 1. Press the BAND button until the XM frequency displays. Press the CAT button to display the c ...