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:
Passenger Sensing System
The vehicle has a passenger sensing system for the
right front passenger position. The passenger airbag
status indicator will be visible on the overhead console
when the vehicle is started.
T ...
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 ...
Your Responsibility
Increase the volume of the radio if the OnStar advisor
cannot be heard.
If the light next to the OnStar buttons is red, the system
may not be functioning properly. Press
and request
a vehicle ...
