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:
Park Brake and P (Park) Mechanism Check
WARNING!
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case ...
DVD Messages
The following errors may be displayed on the
video screen:
Disc Format Error: This message will be
displayed if a disc is inserted upside down, if the
disc is not readable, or if the format is n ...
Maintenance Footnotes
(a) Visually inspect brake lines and hoses for
proper hook-up, binding, leaks, cracks, chafing,
etc. Inspect disc brake pads for wear and rotors for
surface condition. Inspect other brake parts,
i ...
