SERVICE Indicator (4WD)
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The SERVICE indicator (4WD) is an integral part of the cluster and cannot be serviced separately. This indicator is used to inform the driver of malfunctions within the ATC system. The SERVICE indicator (4WD) is controlled by the transfer case shift control module via a Class 2 message or by a service indicator control circuit.