Ford 3C3Z-10884-AA Coolant Temperature Sensor

The engine coolant temperature sensor is mounted near the thermostat housing and is a thermistor, a resistor which varies the value of its resistance in accordance with temperature changes. This change in resistance values directly affects the voltage signal from the sensor to the PCM, with resistance values increasing as sensor temperature decreases and decreasing as sensor temperature increases. Any problem in the ECT sensor circuits will set a diagnostic trouble code. To replace the sensor, ensure the ignition key is in the OFF position and drain approximately one gallon from the cooling system. On 6.0L models, disconnect the wiring connector for the cooling fan, disconnect the electrical connector and carefully unscrew the sensor. On 6.4L engines, remove the air cleaner housing to access the sensor, which is located near the base of the oil filter housing. Wrap the threads of the new sensor with Teflon sealing tape to prevent leakage and thread corrosion. On 6.4L engines, the sensor is sealed with an O-ring, so do not use tape, just install a new O-ring. Installation is the reverse of removal. Note that on later 7.3L and 6.4L models, the ECT sensor is located in the engine front cover.