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:

    Sunroof
    On vehicles with a sunroof, the switch is located on the overhead console. The sunroof only operates when the ignition is in ON/RUN or ACC/ ACCESSORY or in Retained Accessory Power (RAP). See Retai ...

    Reactivation for Subsequent Owners
    Push and follow the prompts to speak to an Advisor as soon as possible after acquiring the vehicle. The Advisor will update vehicle records and will explain the OnStar service offers and opt ...

    Traction Control System (TCS)/StabiliTrak® Light
    The Traction Control System (TCS)/ StabiliTrak Light comes on briefly when the engine is started. If the light does not come on, have the vehicle serviced by the dealer. If the system is working n ...