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Fuel Pressure Sensor – Faults

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Fuel Rail Pressure Sensor Faults

Error code P0193

The fuel pressure sensor is crucial in your diesel engine.

Denso alternate side

Its job is to tell the Engine Control unit (ECU) what pressure of fuel  is in the fuel rail.

The amount of pressurized fuel in the rail will depend on the demands of the driver; at high speed fuel is being used more quickly and will need to be replenished.

As pressure falls the ECU compensates by metering more fuel into the rail from the high pressure pump.

Fuel Rail Pressure Sensor – Faulty

delphi fuel pressure sensor

Fuel Pressure Sensor (FPS) these components do fail.

Some experts claim they are the weakest link in the system, so always suspect the FPS if you get error code P0193.

Some other things to check for with this fault code:

Little or no fuel (at the rail) – this could be due to a problem with the fuel metering valve.
This valve is usually bolted to the back of the high pressure pump; or it can sometimes be found screwed into the end of the common fuel rail itself.

Open circuit or shorting. Check that the wiring in the harness is sound and free of cracks and corrosion etc.

Corrosion can cause poor electrical connection. Eliminate this as a possible fault before buying expensive components or getting involved in hefty repair times.

Faulty high pressure fuel pump.
Check fuel pump for failure. Some pumps are prone to internal component failures.
Pump removal is not always necessary.
Problems can sometimes  be revealed by removing the fuel metering valve and this can be done with the pump still in position on the engine.