O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 1
The P2631 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 1. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $150 - $500 (parts and labor)
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Common Symptoms
- Bank 2 running lean
- Hesitation from bank 2 cylinders
- Higher exhaust temperatures on bank 2
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Bank 2 wideband O2 sensor degraded Very High
- Short to voltage in bank 2 sensor circuit High
- Bank 2 sensor contaminated by coolant Moderate
- ECM bank 2 driver stuck high Low
Frequently Asked Questions
Can a lean bank 2 cause engine damage?
Prolonged lean operation on bank 2 can cause elevated exhaust temperatures, potentially damaging catalytic converters and in extreme cases, causing cylinder damage.
What does coolant contamination on an O2 sensor look like?
A white or crystalline coating on the sensor tip indicates coolant has reached the exhaust system, usually from a head gasket leak or cracked head.
Will P2631 cause a failed emissions test?
Yes. The incorrect bank 2 readings will cause improper fuel trim, likely resulting in high NOx emissions from the lean condition.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Monitor bank 2 pumping current for high readings
-
Check bank 2 wiring for short to power
-
Inspect bank 2 sensor tip for contamination
-
Test ECM bank 2 O2 output
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2010-2020 Toyota Highlander V6
- 2012-2019 Honda Pilot V6
- 2008-2018 Ford Explorer V6
- 2011-2020 Chevrolet Traverse V6
Related Codes
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