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:
How to Detect a Tamper Condition
If is pressed and the
horn
sounds, an attempted break-in
occurred while the system was
armed.
If the alarm has been activated, a
message will appear on the DIC.
See Anti-theft Alarm ...
Your Responsibility
You may need to increase the volume of your
radio to hear the OnStar® advisor. If the light next
to the OnStar® buttons is red, this means that
your system is not functioning properly and should
...
Fuel Additives
To provide cleaner air, all gasolines in the United States are now required to contain additives that help prevent engine and fuel system deposits from forming, allowing the emission control system to ...
