WARNING: This page is about a different car, the 2010 GMC Yukon, 2010 Chevrolet Tahoe, and 2010 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Module Power, Ground, Serial Data, and Stop Lamp Switch
Courtesy of GENERAL MOTORS CORP.
Fig 2: OSS, TFP, TPT, Pressure Controls and Shift Controls