P2002
Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
Diesel Particulate Filter Efficiency Below Threshold (Bank 1): the control module has detected this fault condition.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light or DPF warning light on
- Power loss / limp mode
- Increased fuel consumption
- Failed forced regeneration attempts
Common causes
Ordered by how often each turns out to be the cause.
- DPF heavily loaded — repeated short trips prevent regenerationCommon
- Filter substrate cracked or melted from runaway regenerationPossible
- Differential pressure sensor driftPossible
- Leak around DPF housingLess likely
Parts involved
- Diesel Particulate Filter
- DPF Differential Pressure Sensor
- DPF Temperature Sensor
P2002 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.