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:

    Vehicle Speed Messages
    SPEED LIMITED TO XXX MPH (KM/H) This message displays when your vehicle speed is limited to 128 km/h (80 mph) because the vehicle detects a problem in the speed variable assist steering system. Have ...

    Backing Up
    Hold the bottom of the steering wheel with one hand. To move the trailer to the left, move that hand to the left. To move the trailer to the right, move your hand to the right. Always back up slowly ...

    Lane Departure Warning (LDW)
    For vehicles with this feature, read the entire section before using it. WARNING The LDW system does not steer the vehicle and is an aid to help the vehicle stay in the driving lane. The LDW syste ...