Service Only Mode

This power mode is available for service and diagnostics, and to verify the proper operation of the malfunction indicator lamp as may be required for emission inspection purposes. With the vehicle off, and the brake pedal not applied, pressing and holding the button for more than five seconds will place the vehicle in Service Only Mode. The instruments and audio systems will operate as they do in ON/RUN, but the vehicle will not be able to be driven. The engine will not start in Service Only Mode. Push the button again to turn the vehicle off.

    See also:

    Climate Control Influence on eAssist Operation and Fuel Economy (If Equipped)
    The climate control system is dependent upon other vehicle systems for heat and power input. Certain climate control settings can lead to higher fuel usage and/or fewer auto stops. The follo ...

    How to Detect a Tamper Condition
    If  is pressed and the horn sounds, an attempted break-in occurred while the system was armed. If the alarm has been activated, a message will appear on the DIC. See Anti-theft Alarm ...

    Navigation
    OnStar navigation requires the Directions and Connections service plan. Push to receive directions or have them sent to the vehicle navigation screen. Destinations can also be forwarded to the v ...