P2627

O2 Sensor Pumping Current Trim Circuit Low Bank 1 Sensor 1

Q: Is it safe to drive with P2627?

Yes. This is an emissions/air-fuel measurement fault, not a mechanical one, so the car drives normally. Fix it soon to keep fuel trim and emissions correct.

Q: Can I just clear P2627?

It will clear, but it returns once the sensor or wiring fault reappears. Repair the circuit or replace the sensor to keep it off.

Fuel & air metering Generic OBD-II Low

What it means

P2627 means the ECM detected low voltage in the pumping-current trim circuit of the upstream wide-band oxygen sensor on Bank 1, Sensor 1 — the sensor that measures the exhaust air-fuel ratio. It's a sensor-circuit fault that mainly affects emissions and fuel trim, so the engine keeps running and starting normally; the fix is usually a wiring/connector repair or a new sensor.

Low

Can I keep driving? Safe to drive — the engine still runs and starts normally; you may notice slightly worse fuel economy or a faint rough idle until the sensor circuit is fixed.

Real-world scan data

Seen in

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
Slightly reduced fuel economy
Mild rough idle in some cases
Often no obvious drivability change

Common causes

Most likely first

Low voltage / short in the wide-band O2 sensor's pumping-current trim circuit (Bank 1, Sensor 1)Likely
Corroded, loose, or wrongly-connected sensor connector — sometimes from a previous repairCommon
Chafed or shorted sensor wiringCommon
Failing upstream air/fuel (wide-band) O2 sensorLess often
Less commonly, an ECM faultLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and confirm which sensor is Bank 1, Sensor 1 (the upstream sensor).
Inspect the connector and wiring for corrosion, damage, or a short; verify it isn't mis-wired from earlier work.
Check the sensor's power, ground, and signal circuits against spec.
If the circuit is good, replace the upstream air/fuel sensor and clear the code.
Re-scan after a drive cycle to confirm the fault is gone.

FAQ

Quick answers

Is it safe to drive with P2627?+

Yes. This is an emissions/air-fuel measurement fault, not a mechanical one, so the car drives normally. Fix it soon to keep fuel trim and emissions correct.

Can I just clear P2627?+

It will clear, but it returns once the sensor or wiring fault reappears. Repair the circuit or replace the sensor to keep it off.

Read & clear P2627 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