WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground and Brake Pressure Modulator Valves
Courtesy of GENERAL MOTORS CORP.
Fig 2: Indicators, Stop Lamp, Traction Controls and Serial Data