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:

    Starter Switch Check
    WARNING When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured. 1. Before starting this check, be sure there is enough room around ...

    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 ...

    New Vehicle Break-In
    Notice: The vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines: ○ Do not drive at any one constant speed, fast or slow, for ...