P047BExhaust Pressure Sensor B Circuit Range/Performance
- 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 sensor measures the pressure ahead of the turbine or in the manifold (Ford: turbine upstream pressure, Cummins: exhaust manifold pressure, older Ford diesels: EBP). The module uses it to calculate EGR flow, to control the variable turbine and engine braking, and to protect against overpressure. No manufacturer document available to us uses sensor B – it would be a second sensor, for example on bank 2 of a twin-turbo engine; the description mirrors sensor A. P047B is the plausibility check of sensor B – with the engine off it should read ambient pressure, in operation it should match the model or sensor A (for sensor A Ford uses 15 kPa).
- What you may notice
- Check engine light on
- EGR and turbo control on a substitute value, possibly reduced power
- Exhaust brake or warm-up flap without function
- Likely causes
- LikelySensor drifting or faulty
- LikelySensing tube or hose blocked or coked
- PossibleReal high back pressure from a clogged particulate filter or catalyst
- RareLeaking sensing tube or exhaust leak ahead of the sensor
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.