OBD2 code P0003 is identified as “Fuel Volume Regulator Control Circuit Low,” indicating an issue within the fuel volume control system that results in a lower than expected electrical input.
This code suggests a problem affecting the regulation of fuel to the engine, which can lead to symptoms like hesitation during acceleration, loss of power, or rough idling. It’s crucial for the smooth operation of your vehicle, as the fuel system’s ability to adjust fuel delivery efficiently is compromised.
P0003 quick overview
| Meaning | P0003: Fuel Volume Regulator Control Circuit Low |
| Is it serious? | Yes, it can significantly affect the vehicle’s performance and drivability. |
| Possible causes | – Faults in the fuel pump wiring harness – Damaged or corroded connectors – Faulty fuel volume regulator valve – Issues with the fuel pump control module |
| How to diagnose? | Monitor the fuel pressure and regulator duty cycle to identify when the issue occurs. Load test the regulator wires and wiggle the harness to check for intermittent faults. Perform a voltage drop test on wiring to pinpoint faults. Inspect the fuel pump control module for signs of corrosion on connectors. Repair or replace any damaged wiring from the high pressure fuel pump to the PCM. Check fuel pump relay and fuse for functionality and signs of wear or damage. |
P0003 Meaning
Imagine your vehicle’s fuel system as a sophisticated network of pipes and valves, all controlled by an electrical system to ensure the right amount of fuel reaches your engine at any given time. When the P0003 code pops up, it’s like a warning light for a kink in this system, specifically in the electrical part that tells the fuel volume regulator how much to open or close.
This can lead to all sorts of performance issues, from stuttering starts to a lack of power when you’re trying to accelerate. It’s a critical signal to check out the electronic controls and wiring that manage your fuel flow, ensuring they’re in tip-top shape for optimal performance.
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How to fix P0003 – learn from mechanics
I looked into P0003 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Ford P0003
Vehicle information 2013 Ford Escape SEL 1.6L
Issue + repair history
- Customer complaint of hesitation during driving at 40MPH
- Engine bogs down when accelerating between 4000-4500 RPM
- Scanner showed fuel low pressure at 82psi, but actual test result was 84lbs within spec
- Occurs intermittently, especially under heavy load or brake torqueing
- Check engine light came on and went into reduced power mode
- Code: P0003 – Fuel volume regulator circuit low
Other OBD2 Codes + Test Results
- Low pressure: 84 lbs
- High pressure pump connector resistance: 0.8 ohms
- High pressure pump idling: 711 psi
- High pressure pump at 2500 RPM: 1011 psi
- High pressure pump when bogging: 114 psi
Mechanic suggestions
- Check short term fuel trims and high pressure pump regulator duty cycle during bogging down
- Load test regulator wires and wiggle harness while loading to check for intermittent issues
- Perform voltage drop test on wiring to identify any faults
- Inspect fuel pump control module for corrosion on wires
- Monitor rail pressure while wiggling wiring for fuel volume regulator valve at idle
- Repair broken wiring harness from high pressure fuel pump to PCM
Final fix Repaired broken wiring harness from high pressure fuel pump to PCM, clearing the P0003 code and fixing the intermittent power loss issue.
Case #2: Dodge P0003
Vehicle information 2005 Dodge Sprinter 2500 2.7L
Issue + repair history
- Vehicle stalls after driving 20-30 minutes
- Cranks but doesn’t start for 10-20 minutes, then starts
- Issue occurring more frequently
- Previous facility replaced CDI, cam sensor, repaired wiring at cam/crank sensors, and oil level sensor
- No fuel pressure and cannot hear pump kick on in tank
Other OBD2 Codes + Test Results
- P0305, P1481, P0003, C3700, P292e, P0203, U3112, B0300, B0312, P1354, P0414, P0190
- CKP: 0.7 AC volts when not running, 4.5 volts when running
Mechanic suggestions
- Check fuel pump relay under driver seat and fuse #19 in steering column fuse box
- Inspect crank position sensor for potential issues
Final fix Replaced CKP sensor from MB for the correct year, resolving the issue. The van had a salvaged title with two different VIN numbers and a different engine (2003 model), causing compatibility issues with the parts replaced previously.
Case #3: Toyota P0003
Vehicle information 2010 Toyota Corolla LE 1.8L
Issue + repair history
- Vehicle occasionally experiences loss of power and rough idling
- No significant repair history related to this issue
Other OBD2 Codes + Test Results
- P0003 – Fuel volume regulator circuit low
Mechanic suggestions
- Check fuel pump relay and fuse for any issues
- Inspect wiring harness for potential damage or corrosion
- Perform a fuel pressure test to ensure proper fuel delivery to the engine
Final fix After thorough inspection, it was found that a faulty fuel pump relay was causing intermittent loss of power. Replacing the relay resolved the issue, and the vehicle now runs smoothly without any hesitation.
How to diagnose P0003
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Monitor fuel pressure and regulator duty cycle | Helps identify the issue’s occurrence by observing changes during specific conditions |
| Load test regulator wires and wiggle harness | Checks for intermittent wiring issues that may not be apparent during standard diagnostics |
| Perform a voltage drop test on wiring | Identifies electrical faults that could cause the low circuit signal |
| Inspect the fuel pump control module | Checks for corrosion or damage that could impair its function |
| Repair or replace damaged wiring | Fixes any identified issues in the electrical connection between components |
| Check fuel pump relay and fuse | Ensures that these components are functioning correctly to support the fuel volume regulator |
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko