Failure mode - GM 3.0L Duramax LM2/LZ0 I6 (2020+)

DPF regeneration and ash-loading faults

Reliability tier: aggregated - verify before ordering, see /disclosure/

Symptoms

regen not completing / frequent regens, DPF differential-pressure codes
power loss / derate when ash-loaded beyond limits

Compare with the other causes of the same sign on this engine: loss of power, limp mode or derate (7 causes) · def, dpf and regeneration warnings (4 causes)

Root cause

DPF ash loading and regeneration faults - thin NHTSA record (6), the standard modern-diesel maintenance tail (short-trip duty aggravates it).

Diagnosis

check regen history/soot load before replacing hardware; short-trip duty cycles explain most frequent-regen complaints

Fixes

off-truck DPF cleaning when ash-loaded (service item) ()

DPF cleaning service (professional bake-and-blow, off-truck)

replace the DPF differential-pressure piping when clogged/coded (the sensor itself is not carded in the dealer catalog - verify at order) ()

3.0L Duramax DPF Differential-Pressure Pipe (GM 55496942)

Prevalence

occasional

Affected configurations (42)