What does code P224B mean?

Q: What does code P224B mean?

NOx Sensor Heater Resistance (Bank 1 Sensor 2). P224B indicates that the engine control module has detected an abnormal electrical resistance in the heater circuit of the downstream nitrogen oxide (NOx) sensor on bank 1, which is the sensor after the catalytic converter on that bank. The computer monitors the heater element's current draw during key-on or while the sensor is warming up, and it sets this code when the measured resistance falls outside the expected range for the current temperature.

DTC codes / P22xx · Fuel and air metering (injector circuits) / P224B

P224BNOx Sensor Heater Resistance (Bank 1 Sensor 2)

P224B indicates that the engine control module has detected an abnormal electrical resistance in the heater circuit of the downstream nitrogen oxide (NOx) sensor on bank 1, which is the sensor after the catalytic converter on that bank. The computer monitors the heater element's current draw during key-on or while the sensor is warming up, and it sets this code when the measured resistance falls outside the expected range for the current temperature.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

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