Skip the auto shop - Our mechanics make house calls

P0003 OBD-II Trouble Code: Fuel Volume Regulator Control Circuit Low

check engine light

P0003 trouble code definition

The P0003 code is associated with the electrical circuit which connects to your fuel pressure regulator.

It also may be related to other codes, such as: P0001, P0002, or P0004.

What the P0003 code means

P0003 is a generic OBD-II code indicating an issue with the engine control module (ECM) reading signals from your fuel pressure regulator on your fuel injection rail mounted to your engine.

The ECM regulates your fuel pressure from your fuel pump going to your engine through this circuit and receives input on your actual fuel pressure, from the fuel pressure sensor. When the computer detects that fuel pressure it is not commanding to the fuel pump, it will set a Check Engine Light and this code. The code will affect fuel economy and possibly damage the engine.

What causes the P0003 code?

The fuel volume regulator control circuit low code may have several causes:

  • Possible corrosion in the sensor connector
  • A short in the sensor wiring to the ECM
  • A defective fuel pressure regulator
  • The ECM is damaged

What are the symptoms of the P0003 code?

The P0003 code will produce a Check Engine Light on the instrument panel/dash and will likely affect:

  • Your engine performance during driving
  • Blown fuses
  • Damage to the ECM
  • Possible stalling while driving
  • It may cause the exhaust to show black or white smoke
  • Fuel economy
  • Damage to the catalytic converter in your exhaust

How does a mechanic diagnose the P0003 code?

P0003 is properly diagnosed with an advanced scan tool capable of factory sensor readings (not just one from an auto parts store). A qualified technician can read the data from the advanced scan tool to determine when the problem occurred, or if it is still occurring. They may clear the code/light and test drive the vehicle while monitoring the scan tool data to see if the fault returns or is present.

Wiring may have to be inspected for damage, which requires cutting open the protective covering, inspecting the wiring harness, and replacing the covering.

Based upon the conditions of the testing, possibly clearing the code, and a road test while monitoring the data, further diagnosis may be required. Diagnosis may require multiple tools such as:

  • An advanced scan tool to read the ECM data values
  • A digital voltage meter with attachments
  • A fuel pressure tester

Common mistakes when diagnosing the P0003 code

  • Just replacing the fuel pressure regulator never guarantees a successful repair in resolving your issue. It may be caused by several components in the fuel system and wiring as listed above or more.

  • A visual inspection and testing with special equipment listed above will verify your issue before unnecessarily replacing the fuel pressure regulator.

  • Electrical signals require evaluation by an advanced scan tool, a voltage meter, and a fuel pressure tester to ensure that the fuel pressure regulator requires replacement or if another problem exists. Additional inspection and testing may be required.

How serious is the P0003 code?

The P0003 fault code could cause your vehicle from running and it can:

  • Lower your fuel economy
  • Cause fuel instability which can cause permanent damage to your engine
  • Damage your catalytic converters (which is an expensive repair)
  • Damage your ECM (which requires special programming)
  • Damage your wiring harness
  • Prevent your vehicle from passing emissions

A qualified technician can diagnose the problem with proper tools and time to verify these potential issues and effects to your other systems.

What repairs can fix the P0003 code?

The most common procedure to repair the P0003 code are as follows:

  • Connect a professional scan tool. Verify the code exists.

  • Check for any other fault codes which may be related to the issue, then clear the fault codes to see which fault codes return.

  • Analyze scan tool data from the ECM.

  • Road test the vehicle while analyzing the scan tool data from the ECM with other tools attached.

  • Verify if the P0003 code returns.

  • Inspect all of the items listed above. (wiring, voltages, etc)

  • Further diagnose the problem with the special tools listed above if the problem appears to repeat. The signals and wiring from the sensor require analyzation to determine where the problem exists. If the signals are fine, then further testing of the the wiring, computer, or fuel system is required.

  • Replace the fuel pressure regulator, wiring, ECM (requires programming), or whatever is faulty.

Additional comments for consideration regarding the P0003 code

Any sensor issue may occur all the time or intermittently. Some fault codes will require additional time to diagnose. With this code, the solution may be simple to replace or require extensive time to diagnose and repair. Depending on your vehicle, it may take several hours to determine the root cause and repair the faulty component.

The P0003 code involves many systems and requires extensive diagnosis. After using a scan tool and monitoring the voltage readings, a qualified technician could determine if the fuel pressure regulator, wiring, or ECM is at fault. With the scan tool connected I typically evaluate the data while checking the voltage meter to ensure all the values are adequate and match specifications and do not have shorts in the circuit. If there is not a specified voltage, then a further diagnosis is required.

The sensor may be the cause, wiring issues might be burning/rubbing on another engine component, rodents may have chewed through wiring anywhere in the vehicle, connectors may have shorts or damage, or you may have a bad ECM caused by the short.

An advanced scan tool with specialty tools inspection is required. Then we will determine where the fault lies. We may clear the fault code/light first, then verify if the check engine light returns, and diagnose further. It may have been an intermittent occurrence from weather or some other factor, or a permanent concern.

Vehicles with higher mileage (over 80,000 miles) may just need a fuel pressure regulator replacement. However, replacing parts based upon a code is not recommended and has caused problems or not resolved the issue.

Need help with a P0003 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Post a question and get free advice from our certified mechanics.

ASK A QUESTION

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...


Related questions

Q: Engine light coming on

The diagnosis by another place may be correct, however, the Check Engine Light can go on for many reasons. If you'd like to have a second opinion on the Engine Light or have this service done for you, consider YourMechanic....

Q: Problem starting after fueling have to give it to start

Hello. All modern cars are equipped with an Evaporative Emission Control (EVAP) system. The EVAP system prevents fuel vapors from the fuel tank from escaping into the atmosphere. The EVAP system collects and temporarily stores the fuel vapors in the...

Q: Recently purchased car can't pass a smog check

Hello! I would definitely advise having a basic inspection done before the vehicle is driven on a long trip. Any qualified mechanic, such as one from YourMechanic, will be able to inspect your misfiring issue and let you know if...