Fuel Volume Regulator Control Circuit Low
Code P0003 means the PCM has detected that the fuel volume regulator (FVR) control circuit voltage is lower than its expected minimum threshold. A "circuit low" condition typically indicates a short to ground in the wiring, a failed solenoid drawing excessive current, or a poor ground connection. This code is most common on diesel and gasoline direct injection (GDI) engines that use a high-pressure fuel pump with an FVR solenoid.
What You Might Notice
- Check engine light on
- Hard starting or no-start
- Engine runs rough or stalls at idle
- Reduced power or limp mode
- Hesitation on acceleration
Most Common Causes
- 1
Short to ground in the FVR circuit wiring
A wire in the fuel volume regulator circuit has shorted to ground, pulling the circuit voltage below the PCM's minimum threshold. This is the most common electrical cause of P0003. Inspect the harness for chafing against the engine block or frame.
- 2
Failed FVR solenoid with internal short
An FVR solenoid with a shorted coil draws excessive current, causing the circuit voltage to collapse below normal. Measure solenoid resistance — a reading near zero ohms confirms an internal short.
- 3
Corroded or damaged connector causing high resistance
Severe corrosion in the FVR connector can create a partial short or voltage drop that the PCM reads as a low-circuit condition. Inspect and clean the connector before replacing parts.
- 4
Poor PCM ground connection
A corroded or loose PCM ground strap can cause abnormal circuit voltage readings across multiple sensors. Check all PCM ground connections if P0003 appears alongside other unrelated codes.
How to Diagnose It
- 1
Check Short to ground in the FVR circuit wiring — A wire in the fuel volume regulator circuit has shorted to ground, pulling the circuit voltage below the PCM's minimum threshold. This is the most common electrical cause of P0003. Inspect the harness for chafing against the engine block or frame.
- 2
Check Failed FVR solenoid with internal short — An FVR solenoid with a shorted coil draws excessive current, causing the circuit voltage to collapse below normal. Measure solenoid resistance — a reading near zero ohms confirms an internal short.
- 3
Check Corroded or damaged connector causing high resistance — Severe corrosion in the FVR connector can create a partial short or voltage drop that the PCM reads as a low-circuit condition. Inspect and clean the connector before replacing parts.
- 4
Check Poor PCM ground connection — A corroded or loose PCM ground strap can cause abnormal circuit voltage readings across multiple sensors. Check all PCM ground connections if P0003 appears alongside other unrelated codes.
How to Fix It
- 1
Inspect the FVR wiring harness for shorts to ground
With the FVR disconnected, use a multimeter to check for continuity between the FVR signal wire and ground. Any continuity indicates a short that must be found and repaired before replacing parts.
- 2
Measure FVR solenoid resistance
Connect a multimeter across the FVR solenoid terminals and compare the reading to the manufacturer's specification (typically 1–10 ohms depending on application). A reading near zero confirms a shorted solenoid.
- 3
Clean or replace the FVR connector
A corroded connector is often the root cause of a low-circuit code. Remove, inspect, and clean the connector with electrical contact cleaner. Replace the connector pigtail if pins are badly corroded.
- 4
Replace the fuel volume regulator solenoid
If the solenoid fails resistance testing or the wiring checks out clean, replace the FVR solenoid. On many platforms this is integral to the high-pressure fuel pump.
- 5
Clear codes and verify with a road test
After all repairs, clear DTCs and road test the vehicle. Confirm fuel rail pressure is within spec under all load conditions and that P0003 does not return.
Need a deeper diagnosis?
Search for related repair guides or browse by system.