P2629O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- 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.
- What you may notice
- Check engine light
- Bank 2 fuel control without wide-band feedback
- Possibly further bank 2 fuel trim codes
- Likely causes
- LikelyBank 2 front probe faulty, including heater damage (Mercedes M278/M157)
- PossibleOpen trim wire or loose terminal at the bank 2 probe connector
- RareOutdated engine software (update called for together with new probes)
- 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: €20 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.