Diagnostic Procedure
WARNING: This page is about a different car, the 2002 Nissan Xterra and 2002 Nissan Frontier. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Disconnect ECT sensor harness connector. See Fig 1 or Fig 2 . Turn ignition on. Measure voltage between ground and ECT sensor harness connector terminal No. 1 (Light Green/Red wire). If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short between ECM and ECT sensor.
- Turn ignition off. Check continuity between engine ground and ECT sensor harness connector terminal No. 2 (Black/White wire on 2.4L models; Brown wire on 3.3L models). Continuity should exist. Also, check circuit for short to voltage. If problem is found, go to next step. If problem is not found, go to step 4 .
- Check the following:
- Check for open or short between ECT sensor and ECM.
- On 3.3L models, check Gray, 6-pin joint connector No. 4 (connector F34). Continuity should exist between all terminals. Connector F34 is located near ECM. See Figure or Figure .
On all models, repair as necessary.
- Remove ECT sensor, and place in heated water. Measure resistance between sensor terminals, with water at specified temperatures. See ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, replace ECT sensor.
- No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE
| Temperature - °F (°C) | (1) Ohms | ||
|---|---|---|---|
| 14 (-10) | 7000-11,400 | ||
| 68 (20) | 2100-2900 | ||
| 122 (50) | 680-1000 | ||
| 194 (90) | 236-260 | ||
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