WARNING: This page is about a different car, the 2003 Chevrolet SSR. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground, Serial Data & 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 Schematic (Pressure, Temperature & VSS)
Courtesy of GENERAL MOTORS CORP.
Fig 4: Engine Data Sensors Schematic (Oxygen Sensors)
Courtesy of GENERAL MOTORS CORP.
Fig 5: Engine Data Sensors Schematic (Throttle Actuator Controls)
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Fig 6: Engine Data Sensors Schematic (Ignition Controls - Ignition System Coils 1, 3, 5 & 7)
Courtesy of GENERAL MOTORS CORP.
Fig 7: Engine Data Sensors Schematic (Ignition Controls - Ignition System Coils 2, 4, 6 & 8)
Courtesy of GENERAL MOTORS CORP.
Fig 8: Engine Data Sensors Schematic (Ignition Controls - Sensors)