What does code P22A8 mean?

Q: What does code P22A8 mean?

NOx Sensor Heater Sense Circuit Low (Bank 1 Sensor 2). P22A8 indicates that the powertrain control module has detected an abnormally low voltage on the heater sense circuit for the downstream nitrogen oxide sensor on bank 1. The sensor's heater element is not drawing the expected current, so the computer cannot confirm that the sensor will reach operating temperature for accurate NOx readings.

DTC codes / P22xx · Fuel and air metering (injector circuits) / P22A8

P22A8NOx Sensor Heater Sense Circuit Low (Bank 1 Sensor 2)

P22A8 indicates that the powertrain control module has detected an abnormally low voltage on the heater sense circuit for the downstream nitrogen oxide sensor on bank 1. The sensor's heater element is not drawing the expected current, so the computer cannot confirm that the sensor will reach operating temperature for accurate NOx readings.

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.