P2255 code meaning
O2 Sensor Negative Current Control Circuit Low (Bank 2 Sensor 1)
Powertrain system Generic code P22xx codes Check engine light
What P2255 means
P2255 reports that the negative current control line (reference ground) of the bank 2 upstream wide-band sensor reads too low, typically a short to ground. No manufacturer publicly documents P2255 with thresholds. Ford's OBD summaries assign shorts to ground on any wide-band sensor line to P0151 and use P2254 only for an open line, and VW's 2014 specification books likewise list only P2254. The code therefore appears mainly where the sensor interface separates short-circuit faults by line. CARB requires circuit and out-of-range faults of fuel-control sensors to be detected and, where feasible, stored as separate codes. P2252 is the bank 1 counterpart, P2256 the high-side fault. Mixture control on bank 2 becomes unreliable.
P2255 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2255
- Check engine light
- Higher fuel consumption
- Possible hesitation or uneven running
Common causes of P2255
- Most likelyReference ground wire shorted to ground (chafed against exhaust or body)
- PossibleInternal fault in the wide-band sensor
- Less likelyFault in the sensor interface of the ECM
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank2 sensor1Oxygen sensor wiringECM
What each part of P2255 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| 55 | The exact fault in that area. |
What to do next
- Note P2255 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 P2255
What does P2255 mean?
P2255 means "O2 Sensor Negative Current Control Circuit Low (Bank 2 Sensor 1)". P2255 reports that the negative current control line (reference ground) of the bank 2 upstream wide-band sensor reads too low, typically a short to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P2255?
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 P2255 fail an emissions test?
Yes, it can. P2255 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 P2255 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2255 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.