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:

    Engine Compartment Overview
    5.3 L V8 Engine Shown (4.3 L V6 Engine, 4.8 L V6 Engine, 6.0 L V8 Engine, and 6.2 L V8 Engine Similar) A. Engine Air Cleaner/Filter on page 10‑17. B. Coolant Surge Tank and Pressure Cap. S ...

    Reporting Safety Defects to General Motors
    In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors. Call 1-800-GMC-8782 (1-800-462-8782), or write: GMC Customer Assistance Center P.O. Box ...

    How OnStar Service Works
    Automatic Crash Response, Emergency Services, Crisis Assist, Stolen Vehicle Assistance, Vehicle Diagnostics, Remote Door Unlock, Roadside Assistance, Turn-by-Turn Navigation, and Hands-Free Callin ...