P2628O2 Sensor Pumping Current Trim Circuit High (Bank 1 Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- With P2628 the trim input of the front wide-band probe on bank 1 lies above its permitted range. Ford's 2020-23 petrol summary reserves it for NTK probes, where the interface chip reports the resistor line shorted to battery voltage. In GM's 2005 table for the Honda-sourced 3.5 L V6 it is the opposite end of P2627: the label resistor voltage drops under 0.29 V for 5 s. GM diesels apply it to the NOx sensor oxygen value downstream of the turbine; the 2020 table counts readings above 27 percent, i.e. more oxygen than air, in 100 of 200 samples and only while exhaust pressure is plausible (type B). A trim value out of range skews the lambda value the probe reports, so the module stops trusting the probe. Low is P2627, open P2626, bank 2 high P2631.
- What you may notice
- Check engine light
- Mixture control without probe feedback, higher consumption
- On diesels NOx-related codes and possible SCR warnings
- Likely causes
- LikelyTrim line shorted to battery or another supply in the harness or plug
- PossibleWide-band probe or NOx sensor delivering an implausible value
- RareExhaust leak ahead of the sensor drawing in outside air
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.