OBD-II · Engine and powertrain (P)
P244B
DPF differential pressure too high bank 1
What it means
The pressure difference across the DPF is higher than allowed, meaning the filter is restricting the exhaust - usually because it is loaded with soot or ash.
Symptoms
- reduced power (limp mode)
- DPF warning light and/or engine warning light
- cooling fan running after switch-off or higher idle (regeneration attempts)
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | DPF loaded with soot after failed or interrupted regenerations |
| 02 | high ash load, especially at high mileage |
| 03 | blocked pressure-sensor hose or pressure tapping |
| 04 | faulty differential-pressure sensor |
| 05 | excess soot production from injector, boost or EGR faults |
What to check, step by step
- 01Read pressure, soot and ash estimates and all related faults; verify the pressure reading before diagnosing restriction.
- 02Inspect sensor hoses and pressure tappings and confirm correct routing and a plausible engine-off reading.
- 03Check oil level and dilution before regeneration. Regenerate soot only if all OEM load limits and prerequisites are satisfied, using the approved driving or workshop procedure and fire precautions.
- 04Regeneration does not remove ash. For excessive ash or soot beyond the regeneration limit, arrange approved off-car cleaning or replacement.
- 05Correct the cause of soot accumulation and verify the repair.