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:

    When the Change Engine Oil Soon Message Displays
    Change engine oil and filter. See Engine Oil. An Emission Control Service. When the Change Engine Oil Soon message displays, service is required for the vehicle as soon as possible, within the ne ...

    Exterior Lighting
    The exterior lamp control is located on the instrument panel on the outboard side of the steering wheel. Turn the control to the following positions: : Turns off the exterior lamps. The kn ...

    Owner Checks and Services
    At Each Fuel Stop Check the engine oil level. See Engine Oil . Once a Month Check the tire inflation pressures. See Tire Pressure . Inspect the tires for wear. See Tire Inspection . Che ...