For models from year 2005 onwards where two ECT sensors are fitted, the second sensor is located at thermostat housing. Starting with, turn the key in the ignition lock cylinder and then turn the engine off; this is because, if you do not do this, the coolant will spill out of the crossover when the ECT sensor is pulled out and consequently, it must be replaced with a new one. Then, unscrew the electrical connector from the ECT sensor and, using a wrench, unscrew the actual sensor, which, it should be pointed out, most deep socket may not fit to. It is necessary to remove the faulty sensor and any time a new sensor is being installed or an old sensor is being put back, it is recommended that a new O-ring be fitted. Lastly, replace the sensor as you would do when using the removal process ensuring that the new one is well fixed.