P2254
O2 Sensor Negative Current Control Circuit Low (Bank 2 Sensor 1)
Bank 2 counterpart to P2252. The Vs negative line on the wide-band oxygen sensor at bank 2, sensor 1 is below the lower threshold.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
Ordered by how often each turns out to be the cause.
- Vs negative line shorted to groundCommon
- Nernst cell return open inside sensorPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Oxygen Sensor Upstream B2
- Oxygen Sensor Wiring
P2254 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.