WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Radio Schematic- U1P and UC6
Courtesy of GENERAL MOTORS CORP.
Fig 2: Radio Schematic (U1P and UC6 with UZ6 Amplifier)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Digital Radio Receiver Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: Navigation Radio Schematic - U1A
Courtesy of GENERAL MOTORS CORP.
Fig 5: Navigation Radio Schematic - U1A and Remote CD Changer