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:

    Immobilizer Operation
    This vehicle has PASS-Key® III+ (Personalized Automotive Security System) theft-deterrent system. PASS-Key III+ is a passive theft-deterrent system. The system is automatically armed when the key i ...

    How to Check Lubricant
    2500HD with 6.0 L All Other Series and Engines To get an accurate reading, the vehicle should be on a level surface. • For all 4.3 L, 4.8 L and 5.3 L 1500 Series applications, the proper leve ...

    Child Restraint Systems
    (A) Rear&-Facing Infant Seat A rear-facing infant seat (A) provides restraint with the seating surface against the back of the infant. The harness system holds the infant in place and, in a ...