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:

    TPMS Malfunction Light and Message
    The TPMS will not function properly if one or more of the TPMS sensors are missing or inoperable. When the system detects a malfunction, the low tire pressure warning light flashes for about one m ...

    Auxiliary Battery
    The auxiliary battery provision can be used to supply electrical power to additional equipment that may be added, such as a slide-in camper. If the vehicle has this provision, this relay will be loca ...

    Extended Cab
    On vehicles with a sunroof, the sunroof only operates when the ignition is in the ACC/ACCESSORY or ON/RUN or the Retained Accessory Power (RAP) is active. See Retained Accessory Power (RAP) on page ...