Faulty Fuel Pressure Regulator
Faulty Fuel Pump
Faulty Fuel Pressure Sensor
Engine Light ON (or Service Engine Soon Warning Light)
This fault code is stored in the engine control module when the system cannot correctly control the fuel pressure. The engine control module uses feedback from the fuel pressure sensor to monitor fuel pressure. The fuel pressure regulator circuit integrity is also monitored to ensure the circuit and component is functioning correctly.
Normally manufacturers will support data parameters for actual and desired fuel pressure.
A number of issues may cause this fault code to be set such as a faulty fuel rail pressure sensor, a mechanical fault with fuel pressure regulator could cause the valve to become stuck. An electrical fault such as an open circuit in the fuel pressure regulator on a system with a normally closed valve will also cause this situation. A short circuit on the control wire of a normally open fuel pressure regulator will also cause this fault.
A fault in the fuel injector return system will cause the fuel pressure to be lower than expect. This causes fuel from the high pressure circuit to be leaked back to the low pressure circuit. A faulty maximum pressure relief valve will also cause this situation.
The high pressure pump should also be tested to ensure it is capable of delivering the required volume of fuel.