[3] Water Temperature Sensor (THW made another manufacturer) The water temperature sensor detects the temperature of the engine coolant water and outputs it to the ECU. The sensor uses a thermistor, which varies resistance according to temperature. As the ECU applies voltage to the thermistor, it uses a voltage resulting from the division of the computer internal resistance and the thermistor resistance to detect the temperature. Q000104E ECU VTHW 5 +5V Output voltage (V) 4 VTHW 3 2 A-GND 1 0 -40 -20 0 20 40 60 80 100 120 THW Coolant temperature (°C) Q000105E [4] Fuel Temperature Sensor (THL) The fuel temperature sensor detects the fuel temperature and outputs it to the ECU.
The sensor uses a thermistor, which varies resistance according to temperature. As the ECU applies volt- age to the thermistor, it uses a voltage resulting from the division of the computer internal re- sistance and the thermistor resistance to detect the temperature. ECU VTHL 5 +5V Output voltage (V) 4 VTHL 3 2 A-GND 1 0 -40 -20 0 20 40 60 80 100 120 THL Fuel temperature (°C) Q000106E 15