Honda CR-V 2007-2008
The Engine Coolant Temperature (ECT) sensor uses a thermistor whose resistance changes with the temperature in order to detect the engine coolant temperature. The electrical resistance of the ECT decreases as the temperature increases, and increases as the temperature decreases. The 5-volt reference in the PCM is supplied to the ECT via a resistor in the PCM. The resistor in the PCM and the thermistor in the ECT are connected in series. When the resistance value of the thermistor in the ECT changes according to the engine coolant temperature, the output voltage also changes. During cold engine operation, the PCM increases the fuel injection duration and controls the ignition timing using the information of engine coolant temperature to avoid engine stalling and improve drivability.