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:

    Shifting Into Four-Wheel Drive Low
    When Four-Wheel Drive Low is engaged, vehicle speed should be kept below 72 km/h (45 mph). Extended high-speed operation in Four-Wheel Drive Low may damage or shorten the life of the drivetrain. To ...

    Vehicle Reminder Messages
    CHECK TRAILER WIRING On vehicles with the Integrated Trailer Brake Control (ITBC) system, this message may display and a chime may sound when one of the following conditions exists: • A trailer wi ...

    Engine Coolant Temperature Gauge
    Metric English This gauge measures the temperature of the vehicle's engine. If the indicator needle moves to the hot side of the gauge toward the colored line, the engine is too hot. If ...