Nissan 22630-44B20 Engine Coolant Temperature Sensor

The ECT sensor is located on the coolant crossover pipe which is located at the rear of the engine and is bolted to the rear ends of the two cylinder heads. On 2003 through 2006 G35 Sedans and 350Z models and all G35 Coupes, the ECT sensor is located behind the right cylinder head, near the flange where the crossover pipe is bolted to the right cylinder head. On 2007 and later G35 Sedans and 350Z models, the coolant crossover pipe is slightly different in appearance than the pipe used on earlier models, and the ECT sensor is located at the left end of the crossover pipe, near the flange where the crossover pipe bolts to the left cylinder head. Partially drain the cooling system, to a level that's slightly below the cylinder heads. Disconnect the electrical connector from the ECT sensor. To remove the ECT sensor, depress the release tab and disconnect the electrical connector, then unscrew the ECT sensor from the coolant crossover pipe. Using a deep socket, unscrew the ECT sensor from the coolant crossover pipe. Install a new sealing washer on the sensor. Installation is otherwise the reverse of removal. Be sure to tighten the ECT sensor to the torque. Refill the cooling system.

The coolant temperature indicator system includes a dash warning light or gauge and a coolant temperature sending unit on the engine. The Engine Coolant Temperature (ECT) sensor also acts as the coolant temperature sending unit. If overheating is indicated, check the coolant level and ensure all wiring connectors are secure. The indicator light should come on when the ignition is turned to START, showing the bulb works. If it doesn't, the bulb may be burned out, the ignition switch faulty, or the circuit open. The light should go off once the engine starts unless it overheats. If it stays on, check for trouble codes in the Powertrain Control Module (PCM). If overheating is frequent, check the coolant type and concentration.

The engine cooling temperature sensor is a thermistor that modifies its resistance as the temperature changes. It is screwed into the intake manifold coolant passage on 4-cylinder and 3.3 L V6 models, and into coolant pipe on 3.5 L V6 models. The sensor senses coolant temperature and this information is used by the PCM to compute the engine operating temperature. A problem in the sensor circuit can set a trouble code due to wiring or connection issues or a faulty sensor. Therefore it is important to first check for voltage supply and ground circuits from PCM before checking the sensor. In case voltage supply is not correct, check wiring; if not inspected, PCM may be needed in this case. The resistance between two terminals of this sensor can be measured with ohmmeter. Replace it if the resistance test results are not right.If you replace it, wrap Teflon sealing tape around threads to prevent leakage and corrosion.The old one should be disconnected and removed quickly replaced with new one to minimize coolant loss.They should tightly secure the sensor and reconnect electrical connector. Check coolant level to see whether it needs filling up with coolant or not.Starting engine and allowing it reach normal operating temperature means checking for any leakage of coolant.Coolant level in expansion tank should also be checked after engine has both warmed up and cooled down.

In the engine, the ECT sensor can be found in the water outlet at its leftmost end. To take it out, remove first of all the engine cover and then the air intake duct. Then drain some coolant from the engine to reduce spillage. Then, remove the electrical connector from the ECT sensor. Remove fasteners from engine and discard sealing washer; use new one instead. To fix this back requires reversing. Lastly refill cooling system.

Check the coolant level in the expansion tank after the engine has warmed up and then cooled down again.

If the gauge doesn't respond in the test, the temperature gauge wiring circuit should be checked by a dealer service department or other qualified automotive repair facility.

Installation is the reverse of removal. Refill the cooling system.

Installation is the reverse of removal.