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:

    When the System Does Not Seem to Work Properly
    The following messages may be displayed on the DIC: SERVICE PARK ASSIST: If this message occurs, take the vehicle to your dealer to repair the system. PARK ASST BLOCKED SEE OWNERS MANUAL: This messa ...

    Reclining Seatbacks
    WARNING Sitting in a reclined position when the vehicle is in motion can be dangerous. Even when buckled up, the safety belts cannot do their job when reclined like this. The shoulder belt cannot ...

    Vehicle Overview
    GM says the Sierra 1500 Hybrid's gasoline V-8 and electric motors team up for an overall mileage improvement compared with the regular Sierra. The Sierra Hybrid is only available as a rear- or fou ...