P2455: Diesel particulate filter pressure sensor A circuit high
The ECU sees too high a voltage from the diesel particulate filter pressure sensor. Almost always an electrical fault in a wire or connector.
| Code | P2455 |
|---|---|
| System | Engine and transmission |
| Group | P24xx, EGR, EVAP and particulate filter |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P2455 means
This sensor measures exhaust pressure at the particulate filter, usually the difference between inlet and outlet, so the ECU knows how much soot it holds and when to regenerate. On sensor A the ECU sees a voltage above what is possible, almost always because of an electrical fault. Which sensor is A is set by each manufacturer, though many cars have only one.
Most common causes
- Sensor connector loose or corroded
- Broken sensor earth wire
- Signal wire touching a live wire
- Faulty pressure sensor
- ECU fault (uncommon)
Symptoms
- Engine warning light on
- Possible limp mode with reduced power
- Regenerations delayed or run too often
- Higher fuel consumption if it regenerates frequently
Can you drive with P2455?
With care You can drive, but get it to a garage soon: without this reading the ECU regenerates blindly and the filter can end up blocked.
Open the bonnetthe in-depth explanation
How to check it
With the ignition on and engine off, live differential pressure should read close to zero, and it should rise when you rev the engine at standstill. If it stays fixed or shows silly values, check the sensor connector and pipes.
How to read and clear P2455 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2455 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2451 The evaporative emission system switching valve has got stuck
- P2452 Diesel particulate filter pressure sensor A circuit
- P2453 Diesel particulate filter pressure sensor A range/performance
- P2454 Diesel particulate filter pressure sensor A circuit low
- P2456 The diesel particulate filter pressure sensor A fails now and then
- P2457 The exhaust gas recirculation cooling system gives readings outside the normal
- P2458 Diesel particulate filter regeneration duration
- P2459 Diesel particulate filter regeneration frequency
- P2400 EVAP leak detection pump control circuit open or faulty
- P2413 Exhaust gas recirculation (EGR) system performance
- P2414 O2 sensor exhaust sample error (bank 1, sensor 1)
- P2425 EGR cooler valve control circuit open or faulty
To understand it properly
We explain how that system works, with drawings and no waffle, in our mechanics guide: EGR and particulate filter.
What does code P2455 mean?
This sensor measures exhaust pressure at the particulate filter, usually the difference between inlet and outlet, so the ECU knows how much soot it holds and when to regenerate. On sensor A the ECU sees a voltage above what is possible, almost always because of an electrical fault. Which sensor is A is set by each manufacturer, though many cars have only one.
Can you drive with P2455?
You can drive, but get it to a garage soon: without this reading the ECU regenerates blindly and the filter can end up blocked.
How do you clear P2455?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2455 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
