P24EDNH3 Sensor Calibration Memory
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Every NH3 sensor leaves the factory with individual correction values for offset and gain stored in its own electronics. P24ED means this memory fails its integrity check, for instance a checksum mismatch or unreadable data, so the module cannot convert the raw probe signal into a trustworthy ammonia value. The fix is normally a new sensor; wiring rarely plays a part. It differs from the engine software choice in Ram bulletin 18-042-20, where 2014 Ram 3500 to 5500 cab chassis trucks receive one controller calibration with the ammonia sensor and another without it. No manufacturer documents P24ED publicly. CARB demands that heavy-duty sensors be checked for faults. P24EE covers the sensor processor.
- What you may notice
- Check engine light on
- No valid ammonia value although wiring tests pass
- Likely causes
- LikelyCalibration data in the sensor module corrupted
- RarePower loss while the module was writing data
- 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: €300 – €1,400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.