WARNING: This page is about a different car, the 2009 GMC Savana and 2009 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Module Power, Ground, Serial Data and MIL Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Engine Data Sensors - 5-Volt and Low Reference Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 3: Engine Data Sensors - Pressure, Temperature and Position Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors - Oxygen Sensors Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 5: Throttle Controls Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 6: Ignition Controls - Ignition Control Module Schematic