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:
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with water. ...
Collision Damage Repair
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Vehicle and Power Issues
OnStar services require a vehicle
electrical system, wireless service,
and GPS satellite technologies to be
available and operating for features
to function properly. These systems
may not o ...