P047B code meaning
Exhaust Pressure Sensor B Circuit Range/Performance
Powertrain system Generic code P04xx codes Check engine light
What P047B means
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).
P047B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P047B
- Check engine light on
- EGR and turbo control on a substitute value, possibly reduced power
- Exhaust brake or warm-up flap without function
Common causes of P047B
- Most likelySensor drifting or faulty
- Most likelySensing tube or hose blocked or coked
- PossibleReal high back pressure from a clogged particulate filter or catalyst
- Less likelyLeaking sensing tube or exhaust leak ahead of the sensor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Exhaust pressure sensor bSensor wiringEngine control module
What each part of P047B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 7B | The exact fault in that area. |
What to do next
- Note P047B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P047B
What does P047B mean?
P047B means "Exhaust Pressure Sensor B Circuit Range/Performance". 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). It is a generic code, so it means the same on every make.
Is it safe to drive with P047B?
Drive gently and only to a workshop. With P047B the car can go into limp mode (reduced power) to protect itself.
Will P047B fail an emissions test?
Yes, it can. P047B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P047B to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P047B clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.