P2459: Diesel particulate filter regeneration frequency
The diesel particulate filter is regenerating more often than normal. Usually the engine makes too much soot or a sensor reads wrongly.
| Code | P2459 |
|---|---|
| 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 P2459 means
The ECU keeps track of how often it needs to regenerate, that is, burn off the soot in the particulate filter. If regenerations come far closer together than expected, something is filling the filter too fast, or the ECU thinks it is full when it is not.
Most common causes
- Differential pressure sensor or its pipes giving falsely high readings
- Engine producing excess soot: leaking injector, dirty EGR or intake leak
- Lots of short trips leaving regenerations half done
- Oil consumption fouling the filter
- High ash load in the filter
Symptoms
- Engine warning light on
- Fan running or high idle after switching off, often
- Higher fuel consumption
- Oil level rising (fuel from regenerations dilutes it)
Can you drive with P2459?
With care You can drive, but have it checked soon: frequent regenerations use extra fuel and can dilute the engine oil with diesel, which is bad for the engine.
Open the bonnetthe in-depth explanation
How to check it
Check the oil level on the dipstick: if it is above maximum or smells of diesel, tell the garage. On your scanner, compare the estimated soot load just before and after a regeneration.
How to read and clear P2459 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 P2459 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
- P2455 Diesel particulate filter pressure sensor A circuit high
- 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
- P245A The exhaust gas recirculation cooler bypass control has a broken or
- P245B The exhaust gas recirculation cooler bypass control gives readings outside the
- P245C The exhaust gas recirculation cooler bypass control gives a lower signal than
- P245D The exhaust gas recirculation cooler bypass control gives a higher signal than
- 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
What does code P2459 mean?
The ECU keeps track of how often it needs to regenerate, that is, burn off the soot in the particulate filter. If regenerations come far closer together than expected, something is filling the filter too fast, or the ECU thinks it is full when it is not.
Can you drive with P2459?
You can drive, but have it checked soon: frequent regenerations use extra fuel and can dilute the engine oil with diesel, which is bad for the engine.
How do you clear P2459?
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, P2459 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.
