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:

    Roof
    Sunroof The ignition must be in ON/RUN or ACC/ACCESSORY to operate the sunroof and power sunshade. See Retained Accessory Power (RAP) on page 9‑20. The vehicle may have a sunroof over the fro ...

    Compass Calibration Procedure
    1. Before calibrating the compass, make sure the compass zone is set to the variance zone in which the vehicle is located. See “Compass Variance (Zone) Procedure” earlier in this section. Do not ...

    Vehicle Overview
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