WARNING: This page is about a different car, the 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Navigation System Schematics - Power, Ground, Components And GPS
Courtesy of GENERAL MOTORS CORP.
Fig 2: Navigation System Schematics - Auxiliary RCA Video Jacks And Export Microphone
Courtesy of GENERAL MOTORS CORP.
Fig 3: Navigation System Schematics - Domestic Microphone
Courtesy of GENERAL MOTORS CORP.
Fig 4: Navigation System Schematics - Traffic Information Receiver (VICS)
Courtesy of GENERAL MOTORS CORP.
Fig 5: Navigation System Schematics - TV Antenna Module