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:
Brake Pedal Travel
See your dealer if the brake pedal does not return to normal height, or if there
is a rapid increase in pedal travel. This could be a sign that brake service might
be required. ...
Theft-Deterrent Systems
Vehicle theft is big business, especially in some
cities. Although your vehicle has a number of
theft-deterrent features, we know that nothing we
put on it can make it impossible to steal. ...
Service Bulletins
Service Bulletins give additional
technical service information
needed to knowledgeably service
General Motors cars and trucks.
Each bulletin contains instructions
to assist in the diagnosis ...