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:

    Treadwear 200 Traction AA Temperature A
    The following information relates to the system developed by the United States National Highway Traffic Safety Administration (NHTSA), which grades tires by treadwear, traction, and temperature pe ...

    Driving on Wet Roads
    Rain and wet roads can reduce vehicle traction and affect your ability to stop and accelerate. Always drive slower in these types of driving conditions and avoid driving through large puddles and dee ...

    Front Fog Lamp Light
    For vehicles with front fog lamps, this light comes on when the front fog lamps are in use. The light goes out when the front fog lamps are turned off. See Front Fog Lamps  for more inform ...