O2 Sensor Reference Voltage Circuit High Bank 1 Sensor 1
The P2246 code indicates that the Engine Control Module (ECM) has detected a voltage in the oxygen sensor reference circuit that is higher than the expected range for Bank 1 Sensor 1. This sensor is located upstream of the catalytic converter and is responsible for measuring the oxygen content in the exhaust to help the ECM adjust the air-fuel mixture. A high reference voltage can be caused by a short to voltage in the wiring, a faulty oxygen sensor, or an issue with the ECM itself. This condition can lead to incorrect air-fuel ratio adjustments, reduced fuel economy, and increased emissions.
1. Most Common Causes
- Short to voltage in the O2 sensor signal or reference circuit
- Faulty oxygen sensor (Bank 1 Sensor 1)
- Corroded or damaged wiring/connectors
- ECM internal failure (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation during acceleration
- Failed emissions test
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the O2 sensor wiring and connector for damage, corrosion, or shorts.
Step 3: Measure the reference voltage at the sensor connector with the key on, engine off. Expected voltage is typically 0.45V (varies by manufacturer). If voltage is above 0.5V, suspect a short to voltage.
Step 4: Disconnect the sensor and check the reference voltage at the harness side. If voltage remains high, the issue is in the wiring or ECM. If voltage drops to normal, replace the sensor.
Step 5: Repair any shorted wiring or replace the O2 sensor as needed. Clear the code and test drive.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code as it can cause poor fuel economy and potential damage to the catalytic converter over time. You can drive short distances to a repair shop.
How much does it cost to fix?▼
The cost typically ranges from $150 to $300, including parts and labor. An oxygen sensor costs about $50-$150, and labor is around $100-$150.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.