P2631
O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 1
The wide-band trim resistor circuit on bank 2 sensor 1 reads high. Air-fuel feedback gain on bank 2 is wrong, the controller cannot compensate the offset.
- 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.
- Open calibration trim resistorCommon
- Corroded sensor connectorPossible
- Supply wire pinched against B+ sourceLess likely
Parts involved
- Oxygen Sensor Wideband B2s1
- Sensor Calibration Resistor
- Wiring Harness
P2631 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.