WARNING: This page is about a different car, the 2005 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Cruise Control Switch, Steering Wheel Controls Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 2: Distance Sensing Cruise Control Module Schematics - K59
Courtesy of GENERAL MOTORS CORP.
Fig 3: DLC, Brake Pedal Position Sensor Schematics