F 350 4WD Super Duty V8-6.4L DSL Turbo (2008)
Fuel Temperature Sensor: Description and Operation
FUEL RAIL TEMPERATURE (FRT) SENSOR
Fuel Rail Temperature (FRT) Sensor
The FRT sensor is a thermistor device in which resistance changes with temperature and is located at the base of the secondary fuel filter housing. The
electrical resistance of the thermistor decreases as the temperature increases, and the resistance increases as the temperature decreases. The varying
resistance changes the voltage drop across the sensor terminals and provides electrical feedback signal to the PCM corresponding to temperature. The
FRT sensor measures the temperature of the fuel at the secondary fuel filter and provides a feedback signal to the PCM. The PCM uses the FRT sensor
input to command the correct injector timing, pulse width, and the correct injection control pressure for proper fuel delivery at all speed and load
conditions.
