The fuel rail pressure sensor signals the pressure in the fuel rail to the ECU.
The fuel rail contains a pressurized supply of diesel fuel ready for the fuel injectors to use. When the pressure in the fuel rail drops the fuel pressure sensor signals this to the ECU and the pressure produced by the fuel injection pump is restored. The ECU controls the supply of fuel to the rail from the high-pressure pump; it does this using a Fuel pressure control valve. If the fuel pressure sensor fails or becomes faulty run a diagnostic check on the vehicle.
An illuminated Check Engine Light is another symptom of a potential problem with the fuel rail sensor. If the engine computer detects an issue with the fuel rail sensor signal or circuit, it will set off the Check Engine Light to notify the driver of the problem. The Check Engine Light may also be activated by a wide variety of other issues, so having the computer scanned for trouble codes is highly recommended.
While fuel rail sensors are not in all vehicles, to the ones they are found on, they play a significant role in engine management functions. If your vehicle is displaying any of the symptoms above, or you suspect that your fuel rail sensor may be having an issue, have the vehicle diagnosed by a professional technician, such as one from a Mechanic, to determine if the sensor should be replaced.
Another symptom of a potential problem with the vehicle’s fuel rail sensor is engine performance issues. A faulty rail sensor may upset the air fuel ratio and cause the vehicle to experience performance matters such as a decrease in power, acceleration, and fuel efficiency, and in some cases may even experience stalling.
One of the first symptoms of a potential problem with the fuel rail sensor is hard starting. A faulty fuel rail sensor may send an inaccurate signal to the computer which may cause the engine to experience hard starting. The engine may take a few cranks longer than normal to start and in more severe cases may not start at all.