Powertrain, generic (extended)

P2629 O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2629 is the bank 2 counterpart of P2626 and only exists on V or boxer engines with two front wide-band probes. The module finds the trim branch of that probe interrupted. GM's 2023 table 23OBDG07 calculates the parallel resistance between the probe's APE and MES pins and fails values above 240 ohms as an open compensation resistor, two trips. VW's Touareg V6 and VR6 data book of 2014 uses a probe signal above 4.81 V; Ford checks both banks during deceleration fuel cut for a pure-air reading. Mercedes-Benz bulletin LI49.00-P-054888 (2014) for M278 and M157 V8s blames a damaged probe heater and calls for both upstream probes plus new engine software; Ford's EcoBoost TSB 17-2124 also covers the left-side probe. Bank 2 low and high are P2630 and P2631.

Likely causes

Bank 2 front probe faulty, including heater damage (Mercedes M278/M157)
Open trim wire or loose terminal at the bank 2 probe connector
Outdated engine software (update called for together with new probes)

Symptoms

  • Check engine light
  • Bank 2 fuel control without wide-band feedback
  • Possibly further bank 2 fuel trim codes

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–400
Time0.3–2 h

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

Parts involved

oxygen sensor bank2 sensor1sensor calibration resistoroxygen sensor wiring

Related codes

P2626P2630P2631P2240P2247P2197P0150

References: gsi.ext.gm.com, static.nhtsa.gov, newtonnet.co.uk, static.nhtsa.gov.