P047FExhaust Pressure Control Valve A Stuck Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- The exhaust pressure control valve is a flap in the exhaust: on older Navistar/Ford diesels a warm-up flap that raises back pressure when cold, on Ram and others an exhaust brake, on VW's 2.0 TDI a flap that drives the low-pressure EGR, and on Audi and Bentley a sound flap. P047F means valve A stays open although it is commanded to close, detected by the flap's position sensor or by missing back pressure. On VW's 2.0 TDI and Audi's A3 TDI of 2009–12 the code appears with P0477, P048A–P048C and P0401: water and road salt corrode the flap shaft so the flap sticks; improved parts were introduced. As the flap drives the low-pressure EGR there, EGR flow is then too low.
- What you may notice
- Check engine light on
- EGR flow too low (P0401), higher NOx
- Exhaust brake or warm-up flap without effect, possibly louder exhaust
- Likely causes
- LikelyFlap shaft corroded or seized
- PossibleSoot or carbon on the flap
- PossibleActuator or linkage faulty or unhooked
- RarePosition sensor reports wrongly
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €150 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.