Grand Marquis V8-4.6L VIN V Flex Fuel (2006)
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.
Strain gauge type sensors are considered passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of the
passive sensor causes a variation in total current flow. Voltage that is dropped across a fixed resistor in series with the sensor resistor determines the
voltage signal at the PCM. This voltage signal is equal to the reference voltage minus the voltage drop across the fixed resistor.
The FRP sensor measures the pressure of the fuel near the fuel injectors. This signal is used by the PCM to adjust the fuel injector pulse width and meter
fuel to each engine combustion cylinder.
