P0004
Fuel Volume Regulator A Control Circuit High
Fuel & air metering
Generic OBD-II
High
What it means
P0004 means the ECM has detected an abnormally high voltage in the control circuit for the fuel volume regulator — the valve that meters how much fuel reaches the high-pressure fuel system. Because fuel pressure may no longer be controlled accurately, the engine can start hard, hesitate or stall, so it is worth fixing promptly even if the car still runs.
High
Can I keep driving? Often driveable, but fuel-pressure control is compromised — expect hard starting, hesitation or stalling, so repair it promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting or intermittent stalling
- Hesitation, surging or reduced power under load
- Poor fuel economy
Common causes
Most likely first
- Open, shorted or chafed wiring in the fuel volume regulator control circuitLikely
- Corroded or loose regulator connector pinsCommon
- Failed fuel volume regulator (control solenoid)Common
- Failed ECM driver (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then inspect the regulator connector and harness for corrosion, backed-out pins or chafing.
- Check the control circuit for a short to voltage or an open against the wiring diagram; repair as needed.
- Measure the regulator solenoid resistance and its supply/ground; replace the regulator if out of spec.
- Only after wiring and the regulator check out, suspect the ECM driver. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0004?+
Short trips are usually possible, but inconsistent fuel pressure can cause stalling or a no-start, so treat it as a soon-to-fix item.
Can I just clear P0004?+
It will return until the circuit fault is fixed — this is an electrical circuit code, not a one-off glitch.
Related codes
Often seen with P0004
Read & clear P0004 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX