Fuel Rail Pressure Sensor
The Fuel Rail Pressure (FRP) sensor is located in a threaded port in the forward end of the fuel rail.
The FRP sensor measures the fuel pressure in the fuel rail which is supplied from the High Pressure (HP) fuel pump.
The FRP sensor is a peizo resistor type sensor. The sensor receives a 5V reference voltage from the Powertrain Control Module (PCM). This produces an analogue signal of between 0 and 5V depending on the pressure sensed. Low Pressure (LP) gives a low voltage output and consequently HP gives a higher voltage output. The PCM uses this pressure signal to monitor the fuel pressure in the fuel rail. The PCM controls the fuel pressure in the fuel rail by the HP fuel pump fuel metering valve.
The PCM monitors the FRP sensor for faults and can store fault related Diagnostic Trouble Codes (DTC). These can be retrieved using an approved diagnostic equipment.