Code Definition

P2239 — Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Toyota

About P2239

P2239 is a generic (obd-ii standard) powertrain diagnostic trouble code recorded for Toyota vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P2239 is stored, the module has detected a signal or supply voltage higher than the expected operating range; a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P2239 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The engine control module (ECM) sets P2239 when it detects an abnormally high current in the pumping circuit of the air-fuel ratio (A/F) sensor for Bank 1, Sensor 1. The A/F sensor relies on a controlled pumping current to measure oxygen levels accurately. Excessive current may indicate an internal sensor fault, wiring issue, or ECM malfunction, leading to incorrect fuel mixture adjustments.

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