WARNING: This page is about a different car, the 2008 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground, MIL & DLC Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Engine Data Sensors, 5-Volt Reference Bussing Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 3: Engine Data Sensors, Pressure, Temp & MAF/IAT Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors, HO2S Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 5: Engine Data Sensors, APP & Throttle Body Assembly Schematic