WARNING: This page is about a different car, the 2007 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Rear Video Display Schematic (U42)
Courtesy of GENERAL MOTORS CORP.
Fig 2: TV Tuner Schematic (Export)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Rear Seat Audio and Audio/Video Jacks Schematic