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:

    Security Light
    This light will come on briefly when you turn the key toward START. The light will stay on until the engine starts. If the light flashes, the Passlock® system has entered a tamper mode. If t ...

    Door Locks
    WARNING: Unlocked doors can be dangerous. • Passengers, especially children, can easily open the doors and fall out of a moving vehicle. When a door is locked, the handle will not open it. T ...

    How to Check Automatic Transmission Fluid (4.6L Engine)
    For the 4.6L V8 engine, it is not necessary to check the transmission fluid level. A transmission fluid leak is the only reason for fluid loss. If a leak occurs, take the vehicle to your dealer/ ...