Fuel Temperature Sensor: Description and Operation

Engine Fuel Temperature Sensor (X128)

The Engine Fuel Temperature Sensor is a resistive sensor, located on the fuel rail it measures the temperature of the rail rather than the fuel. The signal is used to increase the injection pulse times when undergoing hot restarts. When the fuel is hot, vaporization occurs in the rail and a "bubble" could form within the injectors. Increasing the pulse times flushes the "bubbles" away and cools the fuel rail with fuel from the tank.