First of all, the orifice for the Engine Coolant Temperature (ECT) sensor 1 is at the right end of the cylinder head and in the thermostat housing. To replace it, drain the engine coolant, remove the high-pressure fuel pump cover on 2015 and later CR-V models, disconnect the sensor's electrical connector, and unscrew the sensor. When fitting it, always adopt a new O-ring. The ECT sensor 2 is located in the lower radiator tank. To replace it, drain the coolant, disconnect the sensor's electrical connector, and unscrew the sensor. When fitting it, always adopt a new O-ring.