WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground and Transfer Case Encoder Motor Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Propshaft Speed Sensors and Front Axle Actuator Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 3: Switch Controls and Class 2 Serial Data Schematic