Circuit Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The SERVICE 4WD indicator is located in the instrument panel cluster (IPC), and shares the common power and ground of the IPC. The transfer case shift control module controls the service indicator by sending the IPC a Class 2 message. This indicator may be controlled with the scan tool using the IPC device controls.