Fuel Temperature Sensor: Description and Operation
DESCRIPTIONThe fuel temperature sensor is integrated in the high pressure fuel pump next to the fuel quantity valve. The sensor detects the temperature of the fuel and supplies that information to the ECM. The sensor ranges from - 40°F (-40°C) to 284°F (140°C). If the engine is cold, the actual value sent will read ambient temperature. The value rises after the engine has been started.
OPERATION
An negative temperature coefficient (NTC) resistor integrated in the fuel temperature sensor alters it's electrical resistance in line with the fuel temperature (the resistance drops as the temperature rises). The ECM uses this reading to calculate optimum engine performance under all driving conditions. If the fuel is to warm, the rail pressure in the system is lowered. The controller quantity of the pressure regulating valve is reduced and the fuel temperature is lowered.