What does code P24ED mean?

Q: What does code P24ED mean?

NH3 Sensor Calibration Memory. P24ED indicates that the powertrain control module has detected a fault in the calibration memory of the ammonia (NH3) sensor, which is used to monitor nitrogen oxide (NOx) reduction in selective catalytic reduction (SCR) systems on diesel vehicles. The computer compares the sensor's internal calibration data against expected values and sets this code when the stored calibration is missing, corrupted, or out of range.

DTC codes / P24xx · Auxiliary emission controls / P24ED

P24EDNH3 Sensor Calibration Memory

P24ED indicates that the powertrain control module has detected a fault in the calibration memory of the ammonia (NH3) sensor, which is used to monitor nitrogen oxide (NOx) reduction in selective catalytic reduction (SCR) systems on diesel vehicles. The computer compares the sensor's internal calibration data against expected values and sets this code when the stored calibration is missing, corrupted, or out of range.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.