What does code P239E mean?

Q: What does code P239E mean?

O2 Sensor Out of Range During Deceleration Bank 1 Sensor 2. P239E means the powertrain control module (PCM) has detected that the downstream oxygen sensor on bank 1 (sensor 2) is reporting a voltage outside its expected range specifically during deceleration fuel cut-off events. The PCM monitors the sensor's response when the engine returns to idle or light load after a period of fuel being cut, and a voltage that stays too high or too low for too long triggers this code.

DTC codes / P23xx · Ignition system and misfire / P239E

P239EO2 Sensor Out of Range During Deceleration Bank 1 Sensor 2

P239E means the powertrain control module (PCM) has detected that the downstream oxygen sensor on bank 1 (sensor 2) is reporting a voltage outside its expected range specifically during deceleration fuel cut-off events. The PCM monitors the sensor's response when the engine returns to idle or light load after a period of fuel being cut, and a voltage that stays too high or too low for too long triggers this code.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaIgnition system and misfire

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