Technical Description of OBD-II Trouble Code
The circuit controlling the fuel volume regulator is experiencing low levels of control.
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code that applies to OBD-II equipped vehicles, such as Ford, Dodge, Vauxhall, VW, Mazda, etc. While it is a generic code, the specific repair steps may vary depending on the make and model of the vehicle.
A P0003 is not a very common trouble code and is typically seen in common rail diesel (CRD) and/or diesel engine, and gasoline direct injection (GDI) equipped vehicles.
This code is related to the electrical system of the fuel volume regulator system. Automotive fuel systems consist of various components, including the fuel tank, fuel pump, filter, lines, injectors, etc. One important component in high pressure fuel systems is the high pressure fuel pump. Its purpose is to increase the fuel pressure to the very high pressure required at the fuel rail for the injectors. These high pressure fuel pumps have a low pressure side and a high pressure side, along with a fuel volume regulator that controls the pressure. In the case of the P0003 code, it indicates an electrical reading that is lower than expected (below the normal range).
This code is related to P0001, P0002, and P0004.
Symptoms
Symptoms of a P0003 DTC may include:
Potential Causes
Potential causes of this engine code may include:
Possible Solutions
First, check for any known Technical Service Bulletins (TSBs) specific to your year/make/model. If there is a TSB that addresses this issue, it can save you time and money during diagnosis.
Next, visually inspect the wiring and connectors related to the fuel volume regulator circuit and system. Look for obvious breaks in the wires, corrosion, etc. Repair any issues as necessary.
The fuel volume regulator (FVR) is a two-wire device with both wires connected to the PCM. Do not apply direct battery voltage to the wires as it could damage the system.
For more specific troubleshooting steps for your year/make/model/engine, refer to a factory service manual.
