WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground, And Stoplamp Switch Signal Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 2: Traction Control Request, DLC, Torque And Steering Position Signals Schematics