WARNING: This page is about a different car, the 2008 Saturn Aura. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground and Serial Data Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Controlled/Monitored Subsystem References Schematic (1 of 4)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Controlled/Monitored Subsystem References Schematic (2 of 4)
Courtesy of GENERAL MOTORS CORP.
Fig 4: Controlled/Monitored Subsystem References Schematic (3 of 4)
Courtesy of GENERAL MOTORS CORP.
Fig 5: Controlled/Monitored Subsystem References Schematic (4 of 4)