WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power Ground, Serial Data, Indicators, Sensors, and References Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Air Bag Modules and Seat Belt Pretensioners Schematic