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:
Blizzard Conditions
Being stuck in snow can be a serious situation. Stay with the vehicle unless
there is help nearby.
If possible, use the Roadside Assistance Program . To get help and keep everyone
in the vehicle ...
Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can
be obtained from your dealer.
...
Compass
Compass Operation
There is a compass display in the upper right corner of
the mirror.
Compass Calibration
Press and hold to activate the
compass calibration
mode. CAL displays in the compass ...
