P2629
O2 Sensor Pumping Current Trim Circuit/Open Bank 2 Sensor 1
Fuel & air metering (O2 sensor)
Generic OBD-II
Low
What it means
P2629 is set when the PCM detects an open or out-of-range pumping-current trim circuit for the upstream wide-band oxygen sensor on bank 2, sensor 1. This sensor helps meter the air/fuel mixture, so a fault mostly affects fuel trim, economy, and emissions rather than drivability. It's usually a wiring/connector problem or a failed air/fuel sensor.
Low
Can I keep driving? Yes — the car drives normally; expect a check-engine light and possibly slightly worse fuel economy and emissions until it's fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Slightly rough or uneven idle
- Reduced fuel economy
- Failed emissions test
Common causes
Most likely first
- Faulty wide-band (air/fuel ratio) O2 sensor, bank 2 sensor 1Likely
- Open or shorted sensor wiringCommon
- Corroded or loose sensor connectorCommon
- Swapped or wrong connectors from a previous repairLess often
- ECM fault (least likely)Less often
How to diagnose & fix
Work through it in order
- Scan freeze-frame data and confirm the code is bank 2, sensor 1 (upstream).
- Inspect the sensor connector and wiring for opens, corrosion, or chafing.
- If the car was recently serviced, verify the upstream O2 connectors aren't swapped.
- Back-probe and test the sensor's pumping-current circuit against spec.
- Replace the air/fuel sensor if it fails; consider the ECM only after wiring checks out.
FAQ
Quick answers
Is it safe to drive with P2629?+
Yes, for normal driving. The engine still runs; you may lose a little fuel economy and it will likely fail an emissions test until the sensor circuit is repaired.
Can I just clear P2629?+
You can, but an open circuit or bad sensor will bring it back within a drive cycle or two. Fix the wiring or sensor to keep it gone.
Related codes
Often seen with P2629
Read & clear P2629 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX