DTC 13: Engine Coolant Temperature (ECT) Sensor

1. Check Power Supply  - Turn ignition off and disconnect ECT sensor harness connector. See Fig 1 . Turn ignition on. Measure voltage between ECT sensor harness connector terminal "a" and ground. See Fig 2 . If voltage is about 5 volts, go to next step. If voltage is not as specified, repair harness or connectors as necessary.
2. Check Ground Circuit  - Turn ignition off. Check for continuity between terminal "b" and engine ground. See Fig 3 . If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Component  - Inspect ECT sensor. See SYSTEM/COMPONENT TESTS article in the ENGINE PERFORMANCE section. Replace ECT sensor if necessary and perform FINAL CHECK  in this article. If ECT sensor is okay, repair ECM pin terminals and/or wiring harness connector.

Fig 1: Locating ECT Sensor Harness Connector (Altima)

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

Fig 2: DTC 13, Checking Power Supply (Altima)

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

Fig 3: DTC 13, Checking Ground Circuit (Altima)

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