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:

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

    Automatic Transmission
    The automatic transmission has a shift lever located on the console between the seats. P (Park): This position locks the front wheels. It is the best position to use when starting the engine becaus ...

    Tire Sidewall Labeling
    Useful information about a tire is molded into the sidewall. The examples show a typical passenger and light truck tire sidewall. Passenger (P-Metric) Tire (A) Tire Size: The tire size code is a c ...