P2627
O2 Sensor Pumping Current Trim Circuit Low Bank 1 Sensor 1
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.
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.
Related codes
Often seen with P2627
Read & clear P2627 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