P244B: Diesel particulate filter differential pressure too high (bank 1)
The pressure difference across the diesel particulate filter is higher than normal. Usually a heavily sooted filter or a blocked sensor tapping.
| Code | P244B |
|---|---|
| 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 P244B means
A sensor compares exhaust pressure before and after the particulate filter. If the difference is very large, the gases are meeting too much resistance: the filter is heavily loaded with soot or ash, or the sensor is giving a reading that is not real.
Most common causes
- Filter heavily loaded because regenerations never finish (lots of short trips)
- Sensor pipe or tapping blocked with soot
- Faulty differential pressure sensor
- High ash load in the filter
- Engine problem producing excess soot: injector, EGR or intake leak
Symptoms
- Engine or DPF warning light on
- Loss of power or limp mode
- Fan running after switch-off or raised idle (regeneration in progress)
- Higher fuel consumption
Can you drive with P244B?
With care You can drive with care, but get to a garage soon. If left, the filter keeps filling and may reach a point where it can only be regenerated or cleaned by a workshop.
Open the bonnetthe in-depth explanation
How to check it
Check the differential pressure and estimated soot load on your scanner. If soot is high and the car allows it, a steady 20 to 30 minute motorway run helps a regeneration finish.
How to read and clear P244B 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 P244B 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
- P2447 The secondary air injection system pump (bank 2) has got stuck
- P2448 The secondary air system is letting in more air than expected
- P2449 There is a fault in the secondary air injection system high air flow (bank 2)
- P244A Diesel particulate filter differential pressure too low (bank 1)
- P244C Exhaust temperature on bank 1 is too low for particulate filter regeneration
- P244D Exhaust temperature on bank 1 is too high for particulate filter regeneration
- P244E Exhaust temperature on bank 2 is too low for particulate filter regeneration
- P244F Exhaust temperature on bank 2 is too high for particulate filter regeneration
- 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 P244B mean?
A sensor compares exhaust pressure before and after the particulate filter. If the difference is very large, the gases are meeting too much resistance: the filter is heavily loaded with soot or ash, or the sensor is giving a reading that is not real.
Can you drive with P244B?
You can drive with care, but get to a garage soon. If left, the filter keeps filling and may reach a point where it can only be regenerated or cleaned by a workshop.
How do you clear P244B?
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, P244B 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.
