Powertrain, generic (extended)

P2627 O2 Sensor Pumping Current Trim Circuit Low (Bank 1 Sensor 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2627 marks a trim signal below its plausible range at the first wide-band probe of bank 1. On Ford petrol engines with NTK probes the interface chip sets it when the resistor line (RL) is open or touches ground; Bosch-equipped Fords do not use it. Honda-built 3.5 L V6 engines in GM's 2005 tables read a label resistor instead and log P2627 when its voltage stays above 4.7 V for 5 s, so the naming follows the resistor value rather than the voltage. On GM diesels the code covers the oxygen signal of the NOx sensor behind the turbine: the 2020 table fails readings below -4 percent in 200 of 250 samples, type B. GM's PIP5468D for 2017-18 Silverado and Sierra with the 6.6 L L5P links P2627 to loose charge-air ducts. Open trim is P2626, high is P2628, bank 2 low is P2630.

Likely causes

Trim/resistor line open or chafed to ground between probe and engine module
Wide-band probe or NOx sensor internally faulty
Loose or leaking charge-air ducts on diesel engines (GM L5P)

Symptoms

  • Check engine light
  • Further oxygen or NOx sensor codes stored at the same time
  • On diesels possibly boost or aftertreatment codes and reduced power

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–450
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

oxygen sensor bank1 sensor1sensor calibration resistornox sensoroxygen sensor wiring

Related codes

P2626P2628P2630P2237P2A00P0299

References: fordservicecontent.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.