P2002 — Diesel Particulate Filter Efficiency Below Threshold
Seen on: 2007+ diesel engines with DPF
Diesel Particulate Filter Efficiency Below Threshold. Common causes: DPF plugged, failed regen, oil contamination.
Your code rides along, so nearby mechanics see the fault before they quote you.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- DPF plugged
- failed regen
- oil contamination
- Faulty DPF differential pressure sensor
- EGR fault
FAQ
Diesel Particulate Filter Efficiency Below Threshold. Common causes: DPF plugged, failed regen, oil contamination.
Serious — Power derate likely — plan to stop soon.
The most common cause is: DPF plugged. Other possibilities include failed regen; oil contamination; Faulty DPF differential pressure sensor; EGR fault.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.