F 350 4WD Super Duty V8-6.4L DSL Turbo (2008)
Fuel Pressure Sensor/Switch: Description and Operation
Fuel Rail Pressure (FRP) Sensor
FUEL RAIL PRESSURE (FRP) SENSOR
Fuel Rail Pressure (FRP) Sensor
The FRP sensor is a diaphragm strain gauge device in which resistance changes with pressure. The electrical resistance of a strain gauge increases as
pressure increases, and the resistance decreases as the pressure decreases. The varying resistance affects the voltage drop across the sensor terminals and
provides electrical signals to the PCM corresponding to pressure. The FRP sensor is located on the fuel rail and its primary function is to provide a
feedback signal to indicate the fuel rail pressure so that the PCM can command the correct injector timing, pulse width, and the correct injection control
pressure for proper fuel delivery at all speed and load conditions. The FRP sensor along with the fuel pressure control valve form a closed loop fuel
pressure control system.
