P2626
O2 Sensor Pumping Current Trim Circuit/Open Bank 1 Sensor 1
Fuel & air metering (O2 sensor)
Generic OBD-II
Medium
What it means
P2626 means the ECM has detected an open or out-of-range pumping-current trim circuit on the upstream (bank 1, sensor 1) oxygen / air-fuel sensor. This circuit lets a wide-band sensor measure the exact air-fuel ratio, so a fault degrades fuel control — the engine keeps running but may idle rough, use more fuel, and produce higher emissions.
Medium
Can I keep driving? Drivable, but expect rougher running, poorer fuel economy, and higher emissions until the sensor circuit is repaired.
Common symptoms
What you'll notice
- Check-engine light on
- Rough or unsteady idle
- Reduced fuel economy
- Hesitation and higher tailpipe emissions
Common causes
Most likely first
- Open or high-resistance in the bank 1 sensor 1 (upstream) O2/air-fuel sensor pumping-current circuitLikely
- Faulty wide-band air-fuel ratio / O2 sensorCommon
- Corroded, loose, or wrongly connected sensor connectorCommon
- Damaged wiring harness to the upstream sensorLess often
- Internal ECM fault (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the bank 1 sensor 1 connector and wiring for corrosion, damage, or a poor connection.
- Confirm the correct sensor is fitted and connectors aren't swapped, especially after recent repairs.
- Check the pumping-current circuit for continuity and correct reference voltage.
- If wiring and connections are good, replace the upstream air-fuel/O2 sensor, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2626?+
Short-term yes, but the engine may run rich or lean, hurting fuel economy and emissions. Fix it soon to avoid wasted fuel and a failed emissions test.
Can I just clear P2626?+
It will come back until the open circuit or faulty sensor is repaired, since the ECM keeps monitoring that signal.
Related codes
Often seen with P2626
Read & clear P2626 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