July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!
Door Control Module Schematics
WARNING: This page is about a different car, the 2004 Isuzu Ascender. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Driver - Power and Ground, and Subsystem References Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Driver - Serial Data and Subsystem References Schematic