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:

    Shifting from Two-Wheel Drive High to Four-Wheel Drive High
    • Shifts between Two-Wheel Drive High and Four-Wheel Drive High can be made at any vehicle speed. • Shift the transfer case lever in one continuous motion into either the Four-Wheel Drive High or ...

    Cold Check Procedure
    Use this procedure only as a reference to determine if the transmission has enough fluid to be operated safely until a hot check procedure can be made. The hot check procedure is the most accurate met ...

    Sun Visors
    Sun Visors Pull the sun visor down to block glare. Detach the sun visor from the center mount to pivot to the side window, or to extend along the rod, if available. ...