P2626

O2 Sensor Pumping Current Trim Circuit/Open Bank 1 Sensor 1

Q: 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.

Q: 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.

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.

Real-world scan data

Seen in

221

scans in the past year

Found in

<0.1%

of scans

0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P2626 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX