P244B
Diesel Particulate Filter Differential Pressure Too HighP244B is a generic OBD-II powertrain diagnostic trouble code: Diesel Particulate Filter Differential Pressure Too High. It is logged by the engine control unit when the dpf monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P244B means
P244B is a generic SAE powertrain trouble code that sets when the engine control module detects that the differential pressure across the diesel particulate filter (DPF) has climbed above the calibrated upper threshold. The differential pressure sensor measures the difference between exhaust pressure upstream and downstream of the filter through two small sample hoses; as soot accumulates inside the substrate, flow restriction rises and the measured delta-P climbs. When the value stays too high to be explained by normal loading, the ECM stores P244B and typically illuminates the malfunction indicator lamp.
The most common underlying condition is a DPF that has become heavily loaded with soot or ash because the regeneration cycles have not been completing successfully. This is often caused by short-trip driving that never lets exhaust temperatures climb high enough, but it can also result from a fault elsewhere in the regeneration chain, an exhaust leak ahead of the filter, blocked or cracked pressure sample hoses, or a drifting differential pressure sensor reporting a false high reading.
Depending on the manufacturer's strategy, the vehicle may enter a reduced-power or limp mode to protect the DPF from thermal damage during a forced regeneration attempt, and continued driving with the code active risks permanently clogging the filter.
Common causes
Most-frequently reported root causes when P244B is logged.
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1
Diesel particulate filter heavily loaded with soot or ash due to incomplete regenerations.
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2
Short-trip or low-load driving pattern that never reaches regeneration temperature.
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3
Faulty or drifting DPF differential pressure sensor reporting an inflated reading.
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4
Blocked, kinked, cracked, or disconnected pressure sample hoses between the DPF and the sensor.
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5
Exhaust leak upstream of the DPF affecting measured pressures.
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6
Wiring or connector fault in the differential pressure sensor circuit.
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7
Related fault preventing regeneration from initiating or completing (for example DEF/SCR or temperature sensor issues).
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8
Use of incorrect engine oil grade leading to accelerated ash loading of the filter.
Symptoms drivers notice
How to diagnose P244B
A typical diagnostic flow when this code is present.
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1
Connect a scan tool, record all stored and pending codes, and note freeze-frame data for P244B.
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2
View live data for DPF differential pressure, exhaust temperatures, and calculated soot load with the engine warm and at idle, comparing values to manufacturer specifications.
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3
Visually inspect the exhaust system for leaks, damage, or loose clamps upstream of the DPF.
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4
Inspect the differential pressure sensor sample hoses for blockage, soot plugging, cracks, or incorrect routing, and clear or replace as needed.
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5
Check the differential pressure sensor and its wiring/connector for damage and confirm its reading at key-on engine-off is near zero.
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6
Address any related regeneration-blocking faults, then attempt a service regeneration with the scan tool and recheck soot load and delta-P.
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7
If soot load remains high after a successful regeneration attempt, evaluate the DPF for ash saturation and consider cleaning or replacement.
Vehicles where we've handled P244B
Platforms in our catalogue with confirmed P244B coverage.
Related powertrain codes
- P2002 — Diesel Particulate Filter Efficiency Below Threshold Bank 1
- P2003 — Diesel Particulate Filter Efficiency Below Threshold Bank 2
- P200C — Diesel Particulate Filter Over Temperature Bank 1
- P200D — Diesel Particulate Filter Over Temperature Bank 2
- P200E — Catalyst System Over Temperature Bank 1
- P226D — Particulate Filter Deteriorated / Missing Substrate Bank 1
Frequently asked questions
Is it safe to keep driving with code P244B active?
Short-term driving is usually possible, but it is not advisable. The filter is already restricted, and continued driving can push it into a heavier loaded or ash-saturated state that may require replacement instead of a simple regeneration.
Will an extended highway drive clear P244B on its own?
Sometimes. If the DPF is only moderately loaded and no other faults are blocking regeneration, a sustained higher-speed drive can let the ECM complete a passive or active regen and the code may clear. If the sensor or hoses are at fault, driving will not help.
Does P244B always mean the DPF needs to be replaced?
No. In many cases the filter itself is fine and the issue is a faulty differential pressure sensor, blocked sample hoses, an exhaust leak, or simply a missed regeneration. Replacement is typically only needed when the filter is ash-saturated or physically damaged.
Can a forced regeneration with a scan tool fix P244B?
It often can, provided the underlying cause is just accumulated soot and no other fault is preventing regeneration. After a successful service regen, the differential pressure and calculated soot load should drop back into the normal range and the code can be cleared.
Disabling P244B in software
RaceTune can permanently disable P244B — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P244B disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch EDC17C50 verified 1 software version
- Bosch EDC17CP09 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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