← DEF / DPF warnings on all engines

Symptoms · 6.7 Cummins 2019+

6.7 Cummins 2019+: def, dpf and regeneration warnings

2 documented failures on this engine list this among their signs. They are ordered from the most widespread down. Each one shows the signs in its record's own words, how to tell it from the others, the usual fix and any recall or bulletin.

1. DPF/SCR aftertreatment problems (2019+ 6.7) Common · 27 complaints · 2 recall/bulletins
2. DEF quality / freezing inducements (2019+ 6.7) Occasional

Not sure which engine you have, or want the recalls for your exact truck? Check your VIN: it names the engine and lists the campaigns for that model year. Whether a recall is still open on your VIN: nhtsa.gov/recalls.

1 DPF/SCR aftertreatment problems (2019+ 6.7)

verified How widespread: Common 27 NHTSA owner complaints match it, out of 318 checked

How it shows up

• 'exhaust filter full' / regen messages; DEF quality warnings; speed-limiting derates
• failed regens on short trips; NOx sensor faults

How to tell it apart

• read soot-load/DEF DTCs first; verify regen completes at highway load
• rule out VGT/EGR faults that block regen conditions

Usual fix

service the aftertreatment path: sensors, DEF quality, DPF cleaning/replacement as indicated

Recalls and bulletins

Emissions Recall Y43Warranty Extension X97 (09-014-22)

Root cause, parts and sources →

2 DEF quality / freezing inducements (2019+ 6.7)

verified How widespread: Occasional

How it shows up

• 'DEF quality low' warnings and countdown to speed limit
• hard derates after cheap/contaminated DEF or a failed DEF heater in freezing weather

How to tell it apart

• read DEF quality/NOx DTCs; test DEF with a refractometer before replacing sensors
• verify DEF heater operation in freezing climates

Usual fix

drain and refill with fresh API-certified DEF; replace failed sensors/heaters as diagnosed

Root cause, parts and sources →

Other symptoms on the 6.7 Cummins 2019+

Hard start, long crank or no-startLoss of power, limp mode or derateWhite smoke from the exhaustLosing coolantTicking, knocking, rattle or whine

Everything on the 6.7 Cummins 2019+Its recalls and bulletins

Order: how widespread each failure is in its record (near-universal, very common, common, occasional, rare), then the number of NHTSA owner complaints that match its keywords. Complaint counts are keyword matches, not a manual review of each complaint. A symptom listed here means the failure is documented with that sign; it is not a diagnosis of your truck. Tiers: verified, aggregated, contested, data-gap. How we tier and source facts.