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:

    Power Liftgate 3/4 Mode
    To program the liftgate opening height: 1. Turn the liftgate switch to either the MAX , or the 3/4 mode position and power open the liftgate. 2. Stop the liftgate movement at the desired height by ...

    Tire Messages
    SERVICE TIRE MONITOR SYSTEM This message displays if there is a problem with the Tire Pressure Monitor System (TPMS). See Tire Pressure Monitor Operation on page 10‑54 for more information. ...

    Fuel Additives
    To provide cleaner air, all gasolines in the United States are now required to contain additives that help prevent engine and fuel system deposits from forming, allowing the emission control syste ...