What does code P22B1 mean?

Q: What does code P22B1 mean?

O2 Sensor Reference Voltage Circuit High (Bank 1 Sensor 2). P22B1 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the reference voltage circuit for the downstream oxygen sensor on bank 1, which is sensor 2 after the catalytic converter. The PCM expects this reference line to sit within a specific low-voltage window, and a sustained high reading tells the module the circuit is open, shorted to voltage, or the sensor's internal electronics have failed.

DTC codes / P22xx · Fuel and air metering (injector circuits) / P22B1

P22B1O2 Sensor Reference Voltage Circuit High (Bank 1 Sensor 2)

P22B1 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the reference voltage circuit for the downstream oxygen sensor on bank 1, which is sensor 2 after the catalytic converter. The PCM expects this reference line to sit within a specific low-voltage window, and a sustained high reading tells the module the circuit is open, shorted to voltage, or the sensor's internal electronics have failed.

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.