P2249O2 Sensor Reference Voltage Circuit Low (Bank 2 Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2249 indicates that the reference voltage circuit of the front air-fuel sensor on bank 2 is pulled too low, most often by a grounded wire in the harness or a fault inside the sensor. The only public manufacturer criteria come from GM's tables for the Saturn Vue 3.5 V6 (L66, 2004-05), a Honda-built engine: after more than 85 s of running with the sensor heater active and the element signal at 3.2-4.6 V, a pump-cell circuit voltage under 1.5 V for half a second stores the code and lights the MIL in that drive cycle. The same table uses P2245 for bank 1. Ford, VW and GM's Bosch-equipped V6 tables do not list P2249. CARB requires circuit faults of fuel-control sensors to be detected. P2247 is the open line, P2250 high, P2255 the low fault of the ground line.
- What you may notice
- Check engine light
- Higher fuel consumption from open-loop fuelling on bank 2
- Possible failed emissions test
- Likely causes
- LikelyReference voltage wire shorted to ground on the bank 2 sensor harness
- PossibleInternal short in the bank 2 air-fuel sensor
- RareFault in the sensor interface of the ECM
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.