6.4L Power Stroke Electrical – FRP (Fuel Rail Pressure)

• The FRP sensor is a (3) wire variable capacitance sensor.
• The ECM supplies a 5 volt reference signal (Vref) which the FRP sensor uses to produce a linear
analog voltage that indicates pressure.
• The primary function of the FRP sensor is to provide a feedback signal to the ECM indicating the pressure of the         fuel in the fuel rail.
• The ECM monitors FRP as the engine is operating to modulate the PCV. This is a closed loop function which                 means the ECM continuously monitors and adjusts for ideal FRP determined by conditions such as load, speed,           and temperature.
• The ECM monitors the FRP signal to determine if the performance of the fuel system is satisfactory.

• During engine operation, if the ECM recognizes that the FRP signal is lower or higher than the value the PCV is           trying to achieve the ECM will set a Diagnostic Trouble Code (DTC) and illuminate the amber malfunction                     indicator lamp on the dash.
• The FRP signal to the ECM is one of the signals used to command the correct injection timing.
• This sensor is replaceable.