WARNING: This page is about a different car, the 1995 Oldsmobile Aurora and 1995 Buick Riviera. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: 3.8L (VIN K & 1) PCM Wiring Diagram (Riviera - 1 Of 3)
Fig 2: 3.8L (VIN K & 1) PCM Wiring Diagram (Riviera - 2 Of 3)
Fig 3: 3.8L (VIN K & 1) PCM Wiring Diagram (Riviera - 3 Of 3)
Fig 4: 4.0L (VIN C) PCM Wiring Diagram (Aurora - 1 Of 3)
Fig 5: 4.0L (VIN C) PCM Wiring Diagram (Aurora - 2 Of 3)
Fig 6: 4.0L (VIN C) PCM Wiring Diagram (Aurora - 3 Of 3)