DTC 13: Engine Coolant Temperature (ECT) Sensor

1. Check Power Supply  - Turn ignition off and disconnect ECT sensor harness connector. Turn ignition on. Measure voltage between ECT sensor harness connector terminal "b" (Yellow/Green wire) and ground. See Fig 1 and Fig 2 . If voltage is approximately 5 volts, go to next step. If voltage is not as specified, verify harness continuity between ECT sensor and ECM. Repair harness or connectors as necessary.
   Fig 1: Locating ECT Sensor Harness Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
   Fig 2: DTC 13, Checking Power Supply

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Check Ground Circuit  - Turn ignition off. Check ECT sensor harness continuity between terminal "a" (Orange/Blue wire) and engine ground. See Fig 3 . If continuity is present, go to next step. If continuity is not present, verify harness continuity between ECT sensor terminal "a" and ECM terminal No. 30 (Orange/Blue wire), and between automatic transmission control unit terminal No. 35 (48-pin connector located on driver side kick panel) and ECT sensor terminal "a" (Orange/Blue wire). Repair harness or connectors as necessary.
3. Check Component  - Inspect ECT sensor. See I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section. Replace ECT sensor if necessary and perform FINAL CHECK  .

Fig 3: DTC 13, Checking Ground Circuit

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