What it means
The powertrain control module detects that the fuel volume regulator control is outside its expected performance range. The code does not by itself identify whether the cause is electrical, mechanical, or fuel-pressure related.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Fuel Volume Regulator A adjusts fuel metering for the high-pressure fuel system, and the control module checks whether the resulting fuel pressure and regulator response match its commands. P0002 sets when that response falls outside the expected range, which can involve the regulator, pump, or pressure feedback rather than a simple open circuit.
Common causes
Most likely first.
- High-pressure pump worn or leaking internally
- Regulator valve sticking from contamination
- Rail pressure sensor reading drifted
Symptoms
- Check engine light on
- Hard starting or hesitation
- Rough running or stalling
- Reduced power
How to diagnose it
- Review freeze-frame data and related codes, then compare commanded and measured rail pressure in live data to identify when the mismatch occurs.
- Inspect the Fuel Volume Regulator A connector and wiring for damage, poor contact, or contamination.
- Check whether the regulator responds consistently to commands using scan-tool data and the manufacturer's test procedure.
- Assess fuel quality and look for signs of contamination that could make the regulator stick.
- If the circuit checks out, test the rail-pressure sensor and high-pressure pump performance against the manufacturer's specification.
Common fixes
- Repair a loose or damaged regulator connector or wiring.
- Address contaminated fuel or fuel-system contamination found during inspection.
- Replace a regulator confirmed to stick or fail testing.
- Repair or replace a worn high-pressure pump or faulty rail-pressure sensor only after confirming the cause.
Can I keep driving?
Hard starting, hesitation, stalling, or reduced power can make driving unpredictable. Avoid high-speed or heavy-load driving, and stop if the engine stalls or loses power significantly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.