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 Cooling System Messages
    ENGINE HOT A/C (Air Conditioning) TURNED OFF This message displays when the engine coolant becomes hotter than the normal operating temperature. See Engine Coolant Temperature Gauge on page 5‑ ...

    Global Positioning System (GPS)
    • Obstruction of the GPS can occur in a large city with tall buildings; in parking garages; around airports; in tunnels, underpasses, or parking garages; or in an area with very dense trees. If GPS ...

    Climate Controls
    A. Fan Control B. Temperature Control C. Air Delivery Mode Control D. Air Conditioning E. REAR (Rear Climate Control) F. Recirculation G. Rear Window Defogger Dual Automatic Climate Control S ...