P2247
O2 Sensor Reference Voltage Circuit/Open Bank 2 Sensor 1
Fuel & air metering (O2 sensor)
Generic OBD-II
Medium
What it means
P2247 means the PCM detected an open in the reference voltage circuit of the bank 2 sensor 1 air-fuel (wideband) sensor. That reference voltage is what the sensor needs to measure the air-fuel ratio, so an open stops it from reporting. It's an electrical fault of the sensor or its wiring; the engine keeps running on backup fueling but with worse economy and emissions until it's repaired.
Medium
Can I keep driving? Usually drivable, but the sensor can't report air-fuel ratio, so fueling runs open-loop with slightly worse economy — fix it soon.
Common symptoms
What you'll notice
- Check-engine light on
- Slightly reduced fuel economy (fueling defaults to open-loop)
- Possible mild hesitation or rough running
- Often no strong driving symptom
Common causes
Most likely first
- Open in the reference voltage circuit of the bank 2 sensor 1 air-fuel (wideband) sensorLikely
- Faulty wideband O2 / air-fuel sensorCommon
- Sensor harness open or shortedCommon
- Poor connection or corrosion at the sensor connectorLess often
- Faulty PCM sensor driver (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the bank 2 sensor 1 connector and wiring for damage or corrosion.
- Check the reference voltage circuit for an open against the wiring diagram.
- Verify the sensor's reference and ground circuits are intact, key on/engine off.
- Repair any open or high-resistance connection in the sensor harness.
- If the circuit is good, replace the bank 2 sensor 1 air-fuel sensor and re-test.
FAQ
Quick answers
Is it safe to drive with P2247?+
Generally yes for the short term — the engine runs on backup fueling, but economy and emissions suffer until the sensor circuit is repaired.
Can I just clear P2247?+
It clears, but returns because this is an open-circuit fault; the wiring or sensor has to be repaired.
Related codes
Often seen with P2247
Read & clear P2247 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX