(3) Coolant Temperature Sensor a. The coolant temperature sensor detects the temperature of the engine coolant and outputs it to the ECU. Q000277E b. 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. VTHW (V) ECU +5V 5 VTHW 4 Output Voltage 3 2 A-GND 1 0 -40 -20 0 20 40 60 80 100 120 (°C) THW -40 -4 32 68 104 140 176 212 248 (°F) Coolant Temperature Q000105E (4) Fuel Temperature Sensor (THL) a. 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 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. VTHL ECU (V) 5 +5V 4 VTHL 3 Output Voltage 2 1 A-GND 0 -40 -20 0 20 40 60 80 100 120 (°C) THL -40 -4 32 68 104 140 176 212 248 (°F) Fuel Temperature Q000106E 26