Fuel Temperature Sensor: Description and Operation

Fuel Temperature (FT) Sensor







The fuel temperature (FT) sensor is installed on the fuel supply pump. It is a variable resistor. The FT sensor has a signal circuit and a low reference circuit. The FT sensor measures the fuel temperature of the fuel. The engine control module (ECM) supplies 5 volts to the FT signal circuit and a ground for the FT low reference circuit. When the FT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the FT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the FT signal circuit.