P2631 code meaning
O2 Sensor Pumping Current Trim Circuit High (Bank 2 Sensor 1)
Powertrain system Generic code P26xx codes Check engine light
What P2631 means
P2631 flags a trim value above the valid window for the first wide-band probe on bank 2. Ford assigns it to NTK probe installations: the interface chip notices the resistor line pulled up to battery voltage, as from a chafed wire touching a powered circuit. GM's 2005 table for the 3.5 L V6 of Honda origin uses the mirror logic, with the bank 2 label resistor voltage below 0.29 V for 5 s. CARB requires front air-fuel ratio sensors to be checked for wiring defects and for readings beyond their valid span that would disable closed-loop fuelling, which is what such a reading does. A harness short can also hit other circuits in the same loom, so check for neighbouring codes first. Bank 1 high is P2628; P2630 is the low fault and P2629 the open fault on this probe.
P2631 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 P2631
- Check engine light
- Lambda control on bank 2 disabled
- Possibly additional circuit codes from the same harness
Common causes of P2631
- Most likelyBank 2 resistor line shorted to a powered wire in the harness
- PossibleBank 2 front probe with internal short
- Less likelyNon-matching replacement probe or repaired connector without the original resistor
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 P2631 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. |
| 31 | The exact fault in that area. |
What to do next
- Note P2631 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 P2631
What does P2631 mean?
P2631 means "O2 Sensor Pumping Current Trim Circuit High (Bank 2 Sensor 1)". P2631 flags a trim value above the valid window for the first wide-band probe on bank 2. It is a generic code, so it means the same on every make.
Is it safe to drive with P2631?
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 P2631 fail an emissions test?
Yes, it can. P2631 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 P2631 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 P2631 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.