P209B: The AdBlue injection air pressure sensor B gives readings outside the normal
The AdBlue injection air pressure sensor B gives readings outside the normal range. It is usually the sensor itself, its wiring or a real fault in what it measures.
| Code | P209B |
|---|---|
| System | Engine and transmission |
| Group | P20xx, Emissions: catalysts and AdBlue |
| Type | Generic: it means the same on every make |
How to read and clear P209B with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P209B with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2097 Post-catalyst fuel trim system too rich (bank 1)
- P2098 Post-catalyst fuel trim system too lean (bank 2)
- P2099 Post-catalyst fuel trim system too rich (bank 2)
- P209A The AdBlue injection air pressure sensor B has an electrical fault
- P209C The AdBlue injection air pressure sensor B gives a lower signal than normal
- P209D The AdBlue injection air pressure sensor B gives a higher signal than normal
- P209E Signals A and B from the reductant injection air pressure sensor disagree
- P209F The AdBlue tank heater control gives readings outside the normal range
- P2002 Diesel particulate filter efficiency below threshold (bank 1)
- P2003 Diesel particulate filter efficiency below threshold (bank 2)
- P2004 Intake manifold runner control stuck open (bank 1)
- P2005 Intake manifold runner control stuck open (bank 2)
What does code P209B mean?
The AdBlue injection air pressure sensor B gives readings outside the normal range. It is usually the sensor itself, its wiring or a real fault in what it measures.
How do you clear P209B?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P209B comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
