Ram Cummins P244B: DPF Differential Pressure Too High
P-Code P244B (FMI N/A) — Diesel Particulate Filter Differential Pressure Too High
Quick Answer
P244B means the DPF differential pressure is higher than expected from soot buildup, usually because regen cycles aren't completing on the truck's typical driving pattern.
Overview: Ram Cummins P-Code P244B
This is your early warning before a soot-load derate. Attempt a full parked regeneration before assuming hardware replacement is needed.
Repair Snapshot
Time
1 - 3 Hours
Difficulty
Intermediate
Parts Cost
$50 - $2,500
Dealer Labor
$400+
Tools Required
- Scan Tool
- DPF Pressure Sensor Hose Inspection Kit
What P-Code P244B Means
P244B means the pressure drop measured across the DPF is higher than expected, indicating the filter is loading with soot faster than regeneration cycles are clearing it, or that the differential pressure sensor/hoses are giving a falsely high reading.
Symptoms Drivers Notice
- Check engine light
- More frequent automatic regeneration attempts
- Slightly reduced fuel economy
- No immediate power loss, but a precursor to a possible derate
Most Likely Root Causes
Regen cycles interrupted before completion
CommonShort trips or driver-cancelled regens never let soot fully burn off.
Predominantly low-speed/idle duty cycle
CommonTrucks that rarely reach highway exhaust temps rely more heavily on active regen.
Cracked or clogged differential pressure sensor hoses
OccasionalGives a falsely elevated reading that doesn't reflect actual filter condition.
Common Misdiagnoses (Don't Waste Parts)
Ordering a new DPF right away
Why it happens: High differential pressure sounds like a clogged filter needing replacement.
Do this instead: Attempt a full parked regeneration first and check sensor hoses.
Ignoring the driving pattern as a cause
Why it happens: Techs focus on hardware.
Do this instead: Ask about the truck's typical routes before assuming a mechanical fault.
Master Tech Commentary
Mechanic's Notes
Shop tip: always check the diff pressure sensor hoses before assuming the DPF itself needs cleaning or replacement - a cracked or clogged hose gives a falsely high reading.
Step-by-Step Diagnostic Procedure
- Step 1: Check DPF soot load percentage and review whether recent regens completed successfully.
- Step 2: Review the truck's typical driving pattern for short trips or heavy idle.
- Step 3: Inspect differential pressure sensor hoses for cracks, disconnection, or soot clogging.
- Step 4: Command a parked regeneration and monitor whether differential pressure decreases as expected.
- Step 5: Check for upstream issues (EGR, boost leak) increasing soot production.
Live Data & Freeze-Frame Tips
Watch the differential pressure value during a commanded parked regeneration - it should trend steadily downward as soot burns off.
Safety Warnings
- Never perform a parked regen near flammable materials or in an enclosed space.
- Allow the exhaust system to cool before inspecting sensor hoses.
When to Limp In vs Tow
Not required at this stage - this is a warning ahead of derate.
Prevention Tips for Fleets & Owner-Operators
- Let scheduled parked regens complete fully.
- For heavy idle/short-haul duty cycles, monitor soot load proactively.
- Inspect diff pressure sensor hoses at PM intervals.
Related Fault Codes
P2459
DPF regeneration frequency fault that often precedes or accompanies this differential pressure warning.
Frequently Asked Questions
Will this code cause a derate?
Not yet - it's a warning stage, but continued unresolved soot accumulation will eventually trigger a derate.
Can I fix this myself?
Often yes, by allowing a full parked regeneration to complete.
Does this mean the DPF needs replacing?
Rarely on the first occurrence - most cases resolve with a successful regen.
Why does my truck get this code more than others?
Duty cycle matters a lot - short-trip or heavy idle trucks build soot faster.
How do I know if the sensor itself is bad?
Inspect the pressure sensor hoses for cracks or soot clogging.