WARNING: This page is about a different car, the 2011 Chevrolet Cruze. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground, and Data Communications and Subsystem References Wiring Schematic (1 of 4)
Courtesy of GENERAL MOTORS CORP.
Fig 2: Subsystem References Wiring Schematic (2 of 4)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Subsystem References Wiring Schematic (3 of 4)
Courtesy of GENERAL MOTORS CORP.
Fig 4: Subsystem References Wiring Schematic (4 of 4)