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:

    If the Off Indicator is Lit for an Adult-Size Occupant
    If a person of adult-size is sitting in the right front passenger seat, but the off indicator is lit, it could be because that person is not sitting properly in the seat. If this happens, use the fo ...

    Compressed Audio or Mixed Mode Discs
    The radio can play discs that contain both uncompressed CD audio and MP3/WMA files. If both formats are on the disc, the radio plays both file formats in the order in which they were recorded to the d ...

    Testing the Alarm
    To test the alarm: 1. From inside the vehicle, lower the driver side window, and open the driver door. 2. Press . 3. Get out of the vehicle, close the door, and wait for the security light to go ou ...