What it means
The oxygen sensor signal circuit is shorted to its heater circuit on Bank 1 Sensor 3. This electrical fault can make the sensor reading unreliable.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 1 Sensor 3 is a third oxygen sensor where the vehicle is equipped with one, and its position and monitoring role vary by design. P2233 means this sensor's signal circuit is shorted to its heater circuit, so the controller cannot rely on its reading for the function assigned to that sensor.
Common causes
Most likely first.
- Signal wire shorted to the sensor heater wire
- Melted or damaged sensor wiring
- Damaged or contaminated connector
- Internal oxygen sensor fault
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
How to diagnose it
- Check vehicle service information to confirm the location and role of Bank 1 Sensor 3, then save freeze-frame data and review its live signal.
- With the exhaust cool, inspect the Sensor 3 connector and harness for melted insulation, chafing, contamination, corrosion, or damage near the exhaust.
- Use the wiring diagram to identify Sensor 3's signal and heater circuits and check for an unintended connection between them.
- Test the harness and connector separately from the sensor to distinguish a wiring short from an internal sensor fault.
- If the sensor and wiring pass, follow the manufacturer's procedure to test the relevant controller input.
Common fixes
- Repair melted or chafed Bank 1 Sensor 3 wiring.
- Clean or repair damaged Sensor 3 connector terminals.
- Replace Bank 1 Sensor 3 if its internal circuits are shorted.
- Repair a controller input fault only if testing confirms it.
Can I keep driving?
If the engine runs normally, a short trip is usually possible, but have the fault addressed soon because the affected oxygen-sensor monitoring and emissions checks may not work correctly. Stop if performance deteriorates or the engine runs roughly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.