WARNING: This page is about a different car, the 2005 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Module Power, Ground, Serial Data and MIL Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 2: Engine Data Sensors - 5 Volt and Low Reference Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 3: Engine Data Sensors - Pressure and Temperature Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors - MAF, VSS and Extended Brake Travel Switch Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 5: Engine Data Sensors - HO2S Schematics
Courtesy of GENERAL MOTORS CORP.
Fig 6: Ignition Controls - Ignition System Sensors Schematics