P3851high severityPowertrain
DPF Regeneration Incomplete - Multiple Attempts
on 2007 Dodge Ram 2500 5.9L I6 Cummins Diesel · 4WD
What this code means
The DPF has failed to complete a regeneration cycle after multiple attempts. Soot loading continues to increase.
Symptoms
- DPF warning light
- Reduced power
- Forced limp mode
- Excessive exhaust temperature warnings
- Strong exhaust smell during regen attempts
- Fuel dilution of engine oil
Common causes
- Driving pattern prevents regen completion (short trips)
- EGR system fault preventing proper temperature
- Injector fault affecting post-injection for regen
- DPF catalyst coating degraded
- Exhaust temperature sensor error
Diagnostic steps
- Check DPF soot loading level
- Review regen history and completion rates
- Test exhaust temperatures during regen attempt
- Check EGR system operation
- Inspect fuel injectors for proper post-injection
Repair notes
Perform forced DPF regeneration with scan tool. If soot loading is critical, DPF cleaning service may be needed. Address root cause preventing regen completion.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1