DTC 84: Automatic Transmission (A/T) Control

1. Check Input Signal Circuit
   
   Turn ignition off. Disconnect ECM and A/T control unit harness connector. See Figure and Fig 1 . Verify harness continuity between ECM connector terminal No. 7 and A/T control unit connector terminal No. 13 (Blue/White wire). See Fig 2 . If continuity is present, go to next step. If continuity is not present, check harness and connectors between ECM and A/T control unit. Repair harness or connectors as necessary and perform FINAL CHECK.
2. Disconnect ECM wiring harness connector. Check connector pins for damage or corrosion. Check all circuit connectors for clean, tight fit. If fault is still present, repeat step 1).

Fig 1: Locating A/T Control Unit Connector (G20)

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: DTC 84, Checking Input Signal Circuit (G20)

Courtesy of NISSAN MOTOR CO., U.S.A.