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:
Engine Compartment Overview
A. Engine Air Cleaner/Filter .
B. Electric Engine Cooling Fan (Out of View). See Cooling System .
C. Engine Oil Dipstick. See “Checking Engine Oil” under Engine Oil .
D. Engine Oil Fill Cap. ...
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the Maintenance II
intervals and replace it at the first oil change after each
50,000 mile (80 000 km) interval. See Scheduled
Maintenance for more information. ...
Battery Replacement
To change the batteries, do the following:
1. Loosen the screw on the battery compartment
door located on the left side of the headphone
earpiece.
2. Replace the two AAA batteries in the
compar ...
