Code Definition

P105D — O2 Sensor Heater Circuit Performance Bank 2 Sensor 2 Stuck ON

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Toyota

About P105D

P105D is a manufacturer-specific 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 P105D is stored, the module has detected a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour; 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.

P105D is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

DTC P105D is set when the Engine Control Module (ECM) detects that the oxygen sensor heater circuit for Bank 2, Sensor 2 remains continuously active or draws more current than expected when it should be switched off. The internal heater brings the sensor element up to operating temperature quickly so the ECM can use the signal for fuel control soon after start up. Bank 2 refers to the cylinder bank that does not contain cylinder number 1, and Sensor 2 is the oxygen sensor located after the catalytic converter. When this circuit stays on or overdraws current, the ECM sets the code and illuminat...

Join TaT to view the complete code information and diagnostic details.

Quick Facts