P2628
O2 Sensor Pumping Current Trim Circuit High Bank 1 Sensor 1
Fuel & air metering
Generic OBD-II
Medium
What it means
P2628 means the engine computer sees high voltage in the pumping-current trim circuit of the upstream wideband oxygen (air/fuel ratio) sensor on bank 1, sensor 1. This sensor helps meter fuel precisely, so a fault usually shows up as slightly worse fuel economy, emissions, and a check-engine light — not a drivability emergency.
Medium
Can I keep driving? Safe to drive short-term — the engine may run slightly rich or lean with worse fuel economy; there's no risk of a no-start.
Common symptoms
What you'll notice
- Check-engine light on
- Slightly rough idle or hesitation
- Reduced fuel economy
- May fail an emissions test
Common causes
Most likely first
- Faulty upstream wideband (air/fuel ratio) sensor, bank 1 sensor 1Likely
- Open or shorted sensor wiring or connectorCommon
- Swapped or wrong sensor connectors from a previous repairCommon
- Corroded connector or poor sensor groundLess often
- Faulty ECM/ECU (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame; confirm bank 1 sensor 1 and check for recent sensor swaps in the vehicle history.
- Inspect the sensor connector and wiring for damage, corrosion, or a wrong connection.
- Check the sensor heater and signal circuits against spec.
- Replace the air/fuel ratio sensor if it reads out of range.
- Clear and drive a few cycles to confirm the fix.
FAQ
Quick answers
Is it safe to drive with P2628?+
Short-term yes — the car won't strand you. But the air/fuel sensor helps meter fuel, so leaving it can hurt fuel economy and emissions. Fix it before an emissions test.
Can I just clear P2628?+
It returns within a few drive cycles unless the sensor or its wiring is repaired. If it followed a recent sensor job, check for swapped connectors first.
Related codes
Often seen with P2628
Read & clear P2628 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