P2627 — O2 Sensor Pumping Current Trim Circuit Low Bank 1 Sensor 1
On a wide-band (broadband) O2 sensor, the trim resistor circuit that calibrates the pumping current is reading low on bank 1 sensor 1. Air-fuel feedback gain is wrong, causing rich or lean offsets.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Oxygen sensor wideband b1s1
- Sensor calibration resistor
- Wiring harness
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Short in the calibration trim resistor
- Water intrusion in the sensor connector
- Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.