P244A: Diesel particulate filter differential pressure too low (bank 1)
The pressure difference across the diesel particulate filter is lower than normal. A loose sensor hose or a damaged filter is typical.
| Code | P244A |
|---|---|
| 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 P244A means
A sensor compares exhaust pressure before and after the particulate filter to work out how much soot it holds. If the difference is almost zero, the ECU concludes the gases are passing through unhindered, as if the filter were cracked, missing, or the sensor were not measuring correctly.
Most common causes
- Differential pressure sensor hose loose, split or melted
- Metal pressure pipe blocked or broken
- Faulty differential pressure sensor
- Exhaust leak between the filter and the sensor tappings
- Particulate filter cracked internally or removed
Symptoms
- Engine warning light on
- Possible limp mode
- Regenerations may not run when due
- Sometimes black smoke from the exhaust
Can you drive with P244A?
With care You can drive, but have it checked soon: without a reliable reading the ECU cannot manage the filter, and if the filter is damaged the car will not meet emissions limits.
Open the bonnetthe in-depth explanation
How to check it
With the engine off, check the two small hoses running from the exhaust to the sensor: properly fitted, not cracked and not swapped over. On live data, the differential pressure should rise clearly when you rev the engine.
How to read and clear P244A 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 P244A 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
- P2446 The secondary air injection system pump (bank 2) has got stuck
- 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)
- P244B Diesel particulate filter differential pressure too high (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
- 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 P244A mean?
A sensor compares exhaust pressure before and after the particulate filter to work out how much soot it holds. If the difference is almost zero, the ECU concludes the gases are passing through unhindered, as if the filter were cracked, missing, or the sensor were not measuring correctly.
Can you drive with P244A?
You can drive, but have it checked soon: without a reliable reading the ECU cannot manage the filter, and if the filter is damaged the car will not meet emissions limits.
How do you clear P244A?
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, P244A 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.
