WARNING: This page is about a different car, the 2007 GMC Yukon XL and 2007 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Module Power, Ground, Serial Data & Stop Lamp Signal Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Shift Controls Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 3: Pressure & Temperature Controls Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: PNP Signal, Speed Signals, & Tow/Haul Signal Schematic