OBD-II code · Powertrain (generic, extended)

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.

Is it safe to drive with P2627?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyShort in the calibration trim resistor
  • PossibleWater intrusion in the sensor connector
  • Less likelyConnector pins corroded - high contact resistance

Symptoms

  • Check engine light on
  • Increased fuel consumption
  • Possible rough idle or hesitation
  • Failed emissions test

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2 h
Emissions test
Likely to fail
Parts involved
Oxygen Sensor Wideband B1s1, Sensor Calibration Resistor, Wiring Harness

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.