WARNING: This page is about a different car, the 2006 GMC Sierra and 2006 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Module Power, Ground, Serial Data, and MIL
Courtesy of GENERAL MOTORS CORP.
Fig 2: Engine Data Sensors - 5-Volt and Low Reference
Courtesy of GENERAL MOTORS CORP.
Fig 3: Engine Data Sensors - Pressure, Temperature, MAF, and VSS
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors - Oxygen Sensors
Courtesy of GENERAL MOTORS CORP.
Fig 5: Ignition Controls
Courtesy of GENERAL MOTORS CORP.
Fig 6: Fuel Pump Controls and Fuel Injectors
Courtesy of GENERAL MOTORS CORP.
Fig 7: Fuel Controls - EVAP and Device Controls
Courtesy of GENERAL MOTORS CORP.
Fig 8: Transmission and Controlled/Monitored Subsystem References