Problem Code Definition P0004
The P0004 code is associated with an electrical circuit that connects to the fuel pressure regulator.
It can also refer to other codes, such as: P0001, P0002 or P0003.
Which means the appearance of the P0004 code
P0004 is not a very common malfunction code and is more common on diesel engines with Common Rail (CRD) and / or diesel engines, and on vehicles with direct gasoline injection (GDI).
P0004 is the general OBD-II code that indicates a problem with the engine control module (ECM) reading the signals from the fuel pressure regulator on the engine’s fuel injection rail.
The ECM regulates the fuel pressure of the fuel pump, receiving information about the actual fuel pressure through this circuit. When the computer detects a pressure that does not fall within the permissible fuel pump pressure range, it sets the engine failure indicator. The code will save fuel and may damage the engine. On the other hand, this code is rare.
What causes the code P0004?
The low fuel volume regulator control circuit code can have several causes:
- Fuel Volume Regulator Solenoid (FVR) Failure
- Cabling / FVR wiring problem (short circuit, corrosion, etc.)
- Plug disconnected for the fuel regulator
- Possible corrosion in the sensor connector.
- Sensor wiring to ECM damaged
- Leakage from the fuel pressure regulator or damage.
- Fuel pump defective
- ECM is damaged.
- Fuel pressure regulator defective
What are the symptoms of P0004 code?
The P0004 code will display an indicator light on the dashboard / engine control panel and may be affected by:
- Malfunction indicator light (MIL)
- The vehicle won’t start
- “Stall mode” on and / or no power
- Reduced engine performance while driving
- It is possible to stop while driving
- May cause exhaust gases to be black or white.
- Damage to the catalyst in the exhaust system
