O2 Sensor Reference Voltage Circuit High Bank 2 Sensor 1
The P2250 code indicates that the Engine Control Module (ECM) has detected a voltage in the reference circuit for the Bank 2 Sensor 1 oxygen sensor that is higher than the specified range. This reference voltage is typically 5 volts and is used by the sensor to operate. A high voltage condition can be caused by a short to voltage in the wiring, a faulty oxygen sensor, or an ECM issue. This code is specific to Bank 2 (the side of the engine not containing cylinder #1) and Sensor 1 (upstream of the catalytic converter).
01. Most Common Causes
- Short to voltage in the O2 sensor wiring or connector
- Faulty oxygen sensor (Bank 2 Sensor 1)
- Corroded or damaged wiring harness
- ECM internal failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or engine misfire
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to verify the code and check for additional codes.
Step 2: Visually inspect the O2 sensor wiring and connector for damage, corrosion, or shorts.
Step 3: Disconnect the O2 sensor and measure the reference voltage at the harness connector (should be ~5V). If voltage is high, repair short to voltage.
Step 4: If reference voltage is correct, test the O2 sensor's internal resistance and output; replace if faulty.
Step 5: Clear codes and test drive to see if code returns.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause poor fuel economy and potential damage to the catalytic converter. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
The cost typically ranges from $150 to $300, including parts and labor. An oxygen sensor costs $50-$150, and labor is about $100-$150.