Service All-Wheel Drive Light
This light should come on briefly when you turn on the ignition, as a check to show you it is working.
The service all-wheel drive light comes on to indicate that there may be a problem with the drive system and service is required. Malfunctions can be indicated by the system before any problem is apparent, which may prevent serious damage to the vehicle. This system is also designed to assist your GM dealer in correctly diagnosing a malfunction.
See also:
Antilock Brake System (ABS)
This vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that helps prevent a
braking skid.
When the engine is started and the vehicle begins to
drive away, ABS c ...
How OnStar® Service Works
In order to provide you with OnStar® services, your
vehicle’s OnStar® system has the capability of
recording and transmitting vehicle information.
This information is automatically sent to an ...
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 ...