This code indicates the engine computer has detected a problem in the heater circuit of the oxygen sensor located on bank 2, sensor 3 position. The heater helps the sensor reach operating temperature quickly; a fault here usually points to an electrical issue in that specific circuit rather than the sensor's sensing element itself.
The internal heating element inside the sensor has burned out or developed an open circuit. This is the most common cause for a dedicated heater-circuit code.
Chafed, melted, or corroded wiring in the sensor heater circuit can interrupt current flow. Rodent damage and road-debris exposure are common contributors.
A damaged, corroded, or loose connector at the sensor can cause high resistance or an open circuit in the heater feed. Pins can push back or corrode over time.
Some vehicles supply the O2 sensor heaters through a dedicated fuse or relay. A blown fuse can disable the heater circuit for one or more sensors.
The internal driver that controls the heater ground or feed inside the PCM has failed. This is rare and should only be considered after all wiring, connectors, and the sensor are verified good.
Usually yes, as the sensor's sensing function may still work once the exhaust warms it. However, cold-start emissions and fuel trim accuracy can be affected until repaired.
No. PCM failure is very rarely the cause. The sensor, wiring, connector, or fuse are far more likely culprits. Replacing the PCM without thorough circuit testing is a common misdiagnosis.
No. Sensor 3 is downstream of the catalytic converter on bank 2 (the side opposite cylinder 1). It is typically a catalyst-monitoring sensor.
No. Only the sensor with the confirmed circuit fault needs replacement, unless testing shows additional sensors have failed independently.