P2629 code meaning
O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 1)
Powertrain system Generic code P26xx codes Check engine light
What P2629 means
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.
P2629 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2629
- Check engine light
- Bank 2 fuel control without wide-band feedback
- Possibly further bank 2 fuel trim codes
Common causes of P2629
- Most likelyBank 2 front probe faulty, including heater damage (Mercedes M278/M157)
- PossibleOpen trim wire or loose terminal at the bank 2 probe connector
- Less likelyOutdated engine software (update called for together with new probes)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank2 sensor1Sensor calibration resistorOxygen sensor wiring
What each part of P2629 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 6 | Area: computer (engine control module) and output circuits. |
| 29 | The exact fault in that area. |
What to do next
- Note P2629 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2629
What does P2629 mean?
P2629 means "O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 1)". P2629 is the bank 2 counterpart of P2626 and only exists on V or boxer engines with two front wide-band probes. It is a generic code, so it means the same on every make.
Is it safe to drive with P2629?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2629 fail an emissions test?
Yes, it can. P2629 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2629 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2629 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.