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:
Driving Across an Incline
Sooner or later, an off-road trail will probably go
across the incline of a hill. If this happens,
you have to decide whether to try to drive across
the incline. Here are some things to consider:
...
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 ...
English and Metric Unit Conversion
To change the display units between English and metric units, see Driver Information
Center (DIC) . ...
