WARNING: This page is about a different car, the 2007 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Cruise Control System Schematics - 2.8L/3.6L (LP1/LY7)
Courtesy of GENERAL MOTORS CORP.
Fig 2: Cruise Control System Schematics - 6.0L (LS2)