P244A DPF differential pressure too low (bank 1)
P244A returns after clearing because a split sensor pipe or a damaged filter doesn't change when the light goes out. We check the pressure readings and pipework at your home, yard or depot and find out which it is.
Why P244A comes back after clearing
The official wording is DPF differential pressure too low (bank 1). A working filter creates a pressure drop as exhaust passes through it, and the ECU expects to see that drop rise with engine speed.
When the difference stays too small, the ECU logs P244A. Clearing it changes nothing about the pipes or the filter, so the next time the engine is worked hard enough for the test, the code comes straight back.
The usual causes behind P244A
| Cause | How it's checked |
|---|---|
| Split, disconnected or swapped sensor pipes | Visual check and pressure readings with the engine revved |
| Cracked or melted DPF letting exhaust straight through | Pressure figures that barely move, sooty tailpipe |
| Filter that has been emptied or removed | Pressure readings and a physical check |
| Faulty differential pressure sensor | Sensor output compared with expected figures |
Symptoms
- The engine or DPF light returning soon after a reset
- Black soot around the tailpipe on a car that used to stay clean
- Regenerations that seem to stop altogether
- Often no change in power, as nothing is blocked
Using the vehicle with P244A showing
Most vehicles run normally, as a low-pressure fault doesn't restrict the exhaust. The lit warning light fails an MOT, though, and if the filter is cracked, soot is going out of the tailpipe instead of being trapped.
Vans and fleets with P244A
On a fleet, P244A often follows exhaust or DPF work where a sensor pipe has been knocked off or refitted the wrong way. We check vans at your yard or depot between jobs, so a quick pipe fix isn't turned into a garage booking.
Businesses that use us often can apply for a trade account on our trade and partners page.
How we stop P244A coming back
Pressure and pipe checks, £100 + VAT
We read the codes, watch the DPF pressure as the engine is revved and check the sensor pipes. You'll know whether it's a pipe, the sensor or the filter itself.
Filter or sensor replacement for road use
A cracked or missing filter on a road vehicle needs a garage to fit a new one. A failed sensor is a smaller garage job. Either way, our findings tell them which.
Reviews
Why does P244A come back after it's been cleared?
The pressure across the filter is still too low, whether from a pipe, sensor or damaged filter, so the next check fails and the code returns.
Can a remap cause P244A?
Not directly. A remap doesn't change the pressure across the filter. A badly set-up map that makes excessive soot and heat could contribute to a cracked filter over time, which a sensible remap avoids.
Can another fault set off P244A?
A failed regeneration that overheated the filter can crack it and lead to P244A later. Codes such as P2002 often appear alongside, as both look at the same pressure figure.
Can you check P244A on our vans at the depot?
Yes. Tell us which vans are showing it and we'll check the pipes and readings on each one.
What should I tell you when I book for P244A?
The registration, the full code and any recent exhaust, DPF or turbo work, as that's often when sensor pipes get disturbed.
Stop P244A coming back
Book a fault check and we'll find out why the DPF pressure is reading low, wherever the vehicle is parked.
More fault codes explained
Eccles, Manchester M30 0SF