P2254O2 Sensor Negative Current Control Circuit/Open (Bank 2 Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2254 concerns the negative current control line - also called reference ground, virtual ground or COM - of the wide-band air-fuel sensor ahead of the catalyst on bank 2. Ford's OBD summaries (2012 and 2020-2023) set it for an open line: with Bosch sensors the PCM briefly injects a reference current and flags the line if lambda barely moves, within about 10 s; with NTK sensors the interface chip reports the open line directly. VW's 2014 Passat and CC books set it when the front signal sits at 1.47-1.52 V while the cell resistance exceeds 950 ohms. P2251 is the same fault on bank 1, P2255/P2256 are low/high faults. Closed-loop mixture control on bank 2 is lost.
- What you may notice
- Check engine light
- Higher fuel consumption from open-loop fuelling on bank 2
- Possible rough running or failed emissions test
- Likely causes
- LikelyBroken reference ground wire or pushed-out pin between sensor and ECM
- PossibleInternal open circuit in the wide-band sensor
- RareCorroded sensor connector with high contact resistance
- 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 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.