WARNING: This page is about a different car, the 2009 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: ECM Power, Ground, Serial Data, and MIL
Courtesy of GENERAL MOTORS CORP.
Fig 2: Engine Data Sensors - 5-Volt and Low Reference 1 of 2
Courtesy of GENERAL MOTORS CORP.
Fig 3: Engine Data Sensors - 5-Volt and Low Reference 2 of 2
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors - Pressure, Temperature, MAF, VSS
Courtesy of GENERAL MOTORS CORP.
Fig 5: Engine Data Sensors - Oxygen Sensors
Courtesy of GENERAL MOTORS CORP.
Fig 6: Engine Data Sensors - Electronic Throttle Controls
Courtesy of GENERAL MOTORS CORP.
Fig 7: Engine Data Sensors - IAT 2, BARO, SCIAP
Courtesy of GENERAL MOTORS CORP.
Fig 8: Ignition Controls - Ignition System Bank 1
Courtesy of GENERAL MOTORS CORP.
Fig 9: Ignition Controls - Ignition System Bank 2
Courtesy of GENERAL MOTORS CORP.
Fig 10: Ignition Controls - CMP Sensors and Solenoids
Courtesy of GENERAL MOTORS CORP.
Fig 11: Crankshaft Position (CKP) Sensor and Knock Sensors