P0061 indicates that the powertrain control module has detected an abnormal resistance in the heated oxygen sensor (HO2S) heater circuit for bank 2 sensor 3. The heater element inside the sensor is not reaching its designed temperature, which can delay closed‑loop fuel control and increase emissions.
The internal heater coil has failed or its resistance is out of specification, preventing the sensor from reaching operating temperature.
Open, shorted, or chafed wires in the heater circuit can cause abnormal resistance readings.
A failed fuse or link cuts power to the heater, leading to a resistance fault.
Poor terminal contact increases resistance and can trigger the code.
An exhaust leak can introduce ambient air that affects sensor temperature and heater performance.
The control module may incorrectly measure heater circuit resistance, but this is an uncommon cause.
The vehicle can usually be driven, but the engine may run less efficiently and emissions will be higher. It is advisable to repair the issue promptly to avoid increased fuel consumption and potential emissions test failures.
In most cases the problem lies in the sensor, wiring, or a blown fuse. PCM failure is a rare cause of P0061, so replacing the control module is usually unnecessary unless other diagnostics confirm it.
Yes. When the heater inside the HO2S fails, the control module detects abnormal resistance and sets P0061. The sensor itself is the most common source of the fault.
Using a multimeter, measure the resistance across the heater terminals of the sensor. If the reading is outside the specification range (often 5–20 Ω for a typical 12 V heater), the heater element is likely failed and the sensor should be replaced.