P225BNOx Sensor Calibration Memory (Bank 1 Sensor 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P225B is stored when the control unit of the downstream NOx sensor on bank 1 cannot provide valid calibration data from its memory. That sensor sits behind the SCR catalyst and is what the engine computer uses to judge how well urea dosing reduces NOx, so a sensor without trustworthy calibration leaves the catalyst monitor blind. Ford lists P225B as a MIL code in its 2014 PCM code table; a description of the check is not public from any manufacturer. Smart NOx sensors of the Continental type keep an OEM-specific calibration in their attached module, which is why a part for another vehicle can trip such a code. P225A is the upstream counterpart, while P229E to P22A1 cover the electrical faults of this downstream sensor.
- What you may notice
- MIL on with no driveability complaint
- SCR efficiency monitor does not complete or reports P20EE
- Possible emissions test failure because readiness stays incomplete
- Likely causes
- LikelyCorrupted or unreadable calibration memory in the downstream NOx sensor module
- PossibleSensor installed with the wrong part number or an OEM calibration for another application
- RareMoisture or corrosion at the sensor module connector disturbing its supply
- 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: €250 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.