U030ESoftware Incompatibility With NOx Sensor B
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- NOx sensor B is usually the downstream sensor after the SCR catalyst, the one whose reading reveals how well the catalyst converts and guides the correction of urea dosing. U030E is stored when its software or calibration identity does not match what the engine controller expects, for instance after a replacement sensor with another part number or a controller update the sensor does not support. Ford's 2014 code interpretation gives U030E the MIL marker, just as for sensor A (U030D). In Ford's 2023 diesel summary sensor B is regarded as lost after about 1 s without frames (U029E), and the 2015 summary also lists invalid data from it (U059F). Without a trusted downstream value the SCR efficiency test cannot run, so readiness stays open; a MIL and, depending on the market, DEF-related warnings follow.
- What you may notice
- MIL and SCR/emission warning
- SCR efficiency monitor never completes
- Possible DEF countdown on some trucks
- Likely causes
- LikelyDownstream NOx sensor replaced with a part of another number or software level
- PossibleUpstream and downstream sensors swapped or coded to the wrong position
- RareEngine controller update requiring a newer sensor version
- 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: €100 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.