WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Powertrain Control Module (PCM) Power And Ground Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Park/Neutral Position Switch Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 3: Transmission Solenoids And Input Shaft Speed Sensor Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: Vehicle Speed Input, Overdrive Switch And Indicator Schematic