What does code P2A3A mean?

DTC codes / P2Axx · Hybrid propulsion / P2A3A

P2A3AO2 Sensor Positive Current Control Circuit High Bank 1 Sensor 3

P2A3A indicates that the powertrain control module (PCM) has detected an abnormally high current on the positive control circuit for the downstream oxygen sensor on bank 1, sensor 3. This sensor is typically the third sensor in the exhaust stream, often used to monitor catalyst efficiency or a separate bank. The PCM commands a specific current to the sensor's pump cell, and the feedback circuit reports a current higher than expected, which can be caused by a short to voltage, a faulty sensor, or a wiring issue.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

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