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P0150 — O2 Sensor Circuit Bank 2 Sensor 1

Generic OBD-II · all makesPowertrain (engine & transmission)

P0150 indicates a malfunction in the oxygen sensor circuit for Bank 2, Sensor 1 (upstream). This code is set when the engine control module detects an abnormal voltage, current, or response time from the sensor's heater or signal circuit, often due to a failed sensor or wiring issue.

Symptoms

What causes it — most likely first

1. Faulty oxygen sensor (Bank 2, Sensor 1)

The most common cause. The sensor's internal heater or sensing element fails, causing incorrect voltage or no signal.

2. Damaged or corroded wiring/connector

Wires to the sensor can be chafed, melted, or corroded, especially near the exhaust, breaking the circuit.

3. Exhaust leak upstream of the sensor

An exhaust leak allows outside air to enter, diluting the exhaust and causing the sensor to read lean, triggering the code.

4. Blown fuse or faulty relay for O2 sensor heater circuit

The sensor heater requires power; a blown fuse or defective relay will prevent the heater from operating, setting the code.

5. Engine control module (PCM) failure

Rare, but possible if the PCM's internal driver for the O2 sensor heater or signal input is damaged. This should only be considered after all other causes are ruled out.

How it's diagnosed

  1. Retrieve all stored codes and freeze-frame data to confirm P0150 and check for related codes (e.g., P0135 for heater circuit).
  2. Visually inspect the O2 sensor wiring and connector for damage, corrosion, or loose connection; repair as needed.
  3. Check the oxygen sensor heater circuit: measure resistance across the heater pins (typically 3–15 ohms) and verify 12V power and ground at the connector with the ignition on.
  4. Test the sensor signal: with a scan tool, monitor the O2 sensor voltage; it should cycle between 0.1V and 0.9V at operating temperature. A stuck voltage (e.g., 0.45V) indicates a failed sensor.
  5. Inspect for exhaust leaks near the sensor (manifold, flex pipe, gaskets) using a smoke machine or by listening for ticking sounds; repair leaks if found.
  6. If all tests pass, check for PCM software updates or perform a PCM reset; only replace the PCM as a last resort after verifying all wiring and sensor integrity.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make
Related codesP0148 — Fuel Delivery ErrorP0149 — Fuel Timing ErrorP0151 — O2 Sensor Circuit Low Voltage Bank 2 SP0152 — O2 Sensor Circuit High Voltage Bank 2 P0153 — O2 Sensor Circuit Slow Response Bank 2P0154 — O2 Sensor Circuit No Activity Detected

Frequently asked

Can I drive my car with a P0150 code?

Yes, but it is not recommended for long distances. The engine may run rich or lean, reducing fuel economy and potentially damaging the catalytic converter over time.

Do I need to replace the PCM for P0150?

Almost never. The PCM is rarely the cause. Most cases are fixed by replacing the oxygen sensor or repairing wiring. Only consider PCM replacement after thorough diagnosis of all other components.

Will cleaning the oxygen sensor fix P0150?

No. Oxygen sensors are not serviceable; cleaning does not restore proper function. Replacement is the only reliable fix if the sensor is faulty.

Is P0150 the same as P0130?

No. P0130 is for Bank 1, Sensor 1. P0150 is for Bank 2, Sensor 1. The diagnostic steps are similar, but the sensor location is different.