O2 Sensor Reference Voltage Circuit Open Bank 2 Sensor 1
Code P2247 indicates an open circuit in the reference voltage supply to the oxygen sensor located before the catalytic converter on Bank 2 (the side of the engine not containing cylinder #1). The sensor's heater circuit or signal reference wire may be broken, preventing the sensor from operating. This can cause the engine control module (ECM) to detect a missing or erratic signal, leading to improper air-fuel mixture adjustments.
1. Most Common Causes
- Open or shorted wiring in the O2 sensor circuit
- Damaged O2 sensor connector
- Blown fuse for the O2 sensor heater circuit
- Faulty O2 sensor (Bank 2 Sensor 1)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation
- Failed emissions test
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm code P2247 and check for additional codes.
Step 2: Visually inspect the O2 sensor wiring and connector for damage, corrosion, or loose connections.
Step 3: With a multimeter, check for 12V at the heater power wire and ground continuity at the sensor connector.
Step 4: If power and ground are present, test the sensor's signal reference voltage (typically 0.45V) from the ECM; if missing, repair the open circuit.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but it may cause poor performance and increased emissions. Prolonged driving can damage the catalytic converter.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Replacing the sensor adds $100-$200, while wiring repairs may be $50-$150.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.