P244D
Exhaust Particulate Filter Restriction - Regeneration IncompleteP244D is a generic OBD-II powertrain diagnostic trouble code: Exhaust Particulate Filter Restriction - Regeneration Incomplete. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P244D means
DTC P244D is set when the PCM or diesel particulate filter (DPF) control module determines that a regeneration cycle was initiated but did not complete successfully, and the particulate filter restriction level remains above the acceptable threshold. Regeneration is the process of burning accumulated soot out of the DPF substrate by raising exhaust temperature, either passively during sustained highway driving or actively through post-injection fuel strategies.
An incomplete regeneration can occur if the vehicle was shut down before the cycle finished, if exhaust temperatures could not be sustained at the required level due to a faulty fuel injector post-injection system, a failing glow plug circuit on the DOC, or insufficient engine load. Repeated incomplete regenerations lead to progressive soot accumulation until the filter reaches a critically blocked state requiring forced regeneration or physical cleaning.
Diagnosis must distinguish between a filter that failed to regenerate due to a vehicle usage pattern (frequent short trips) versus an active fault in the regeneration control system such as a failed injector, oxidation catalyst, or exhaust temperature sensor. Reviewing the DPF differential pressure PID and exhaust temperature sensor data is essential.
Common causes
Most-frequently reported root causes when P244D is logged.
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1
Vehicle shut down mid-regeneration cycle before completion.
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2
Frequent short trips preventing passive regeneration temperatures from being reached.
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3
Faulty post-injection fuel delivery preventing active regeneration temperature targets.
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4
Failed or degraded diesel oxidation catalyst (DOC) upstream of the DPF.
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5
Exhaust temperature sensor fault providing inaccurate feedback to the regeneration controller.
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6
Excessive oil consumption contaminating the DPF and inhibiting soot combustion.
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7
DPF differential pressure sensor fault causing incorrect soot load estimation.
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8
High ash loading in a high-mileage DPF that can no longer fully regenerate.
Symptoms drivers notice
How to diagnose P244D
A typical diagnostic flow when this code is present.
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1
Retrieve all DTCs and note any exhaust temperature sensor, differential pressure sensor, or post-injection codes.
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2
Check the DPF soot load and ash load values with a scan tool capable of reading DPF-specific PIDs.
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3
Review exhaust temperature sensor readings across all positions to confirm sensors are reading plausible values.
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4
Check differential pressure sensor operation and compare to known good values for the current soot load.
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5
Perform a forced stationary regeneration with a scan tool if soot load is within the regenerable range and no active component faults are present.
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6
Inspect the DOC and DPF for ash overloading or physical damage if forced regeneration fails to reduce soot load.
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7
Address any underlying fuel system, temperature sensor, or injection faults before condemning the DPF.
Vehicles where we've handled P244D
Platforms in our catalogue with confirmed P244D coverage.
Related powertrain codes
- P2400 — Evaporative Emission System Leak Detection Pump Control Circuit/Open
- P2401 — Evaporative Emission System Leak Detection Pump Control Circuit Low
- P2402 — Evaporative Emission System Leak Detection Pump Control Circuit High
- P2404 — EVAP Leak Detection Pump Sense Circuit: Implausible Signal
- P2405 — Evaporative Emission System Leak Detection Pump Sense Circuit Low
- P2407 — Evaporative Emission System Leak Detection Pump Sense Circuit Intermittent/Erratic
Frequently asked questions
Can I clear P244D without doing a forced regeneration?
Clearing the code without completing a regeneration will cause it to return quickly if the soot load remains elevated. A successful forced or passive regeneration is needed to address the underlying condition.
How do I complete a passive regeneration after P244D?
Drive at sustained highway speeds (typically above 60 km/h) for 30-60 minutes with moderate to high engine load. This raises exhaust temperatures enough to passively burn accumulated soot, provided the soot load is not critically high.
Will P244D damage the DPF if ignored?
Yes. Progressive soot accumulation eventually causes backpressure severe enough to reduce engine power and can lead to physical filter damage or melting if the ECU attempts a forced regeneration on an overly loaded filter.
Does P244D mean the DPF needs replacement?
Not necessarily. P244D indicates regeneration did not complete, not that the filter is failed. If the soot load is in range and no other component faults exist, a successful forced or driven regeneration will often resolve it without replacement.
Disabling P244D in software
RaceTune can permanently disable P244D — 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 P244D 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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