WARNING: This page is about a different car, the 2004 Cadillac Seville. 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 and Temperature Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors - HO2S Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 5: Ignition Coil/Module 1,3,5, and 7 Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 6: Ignition Coil/ Modules 2,4,6, and 8 Schematic