P246B
Vehicle Conditions Incorrect for Particulate Filter Regeneration
The driving pattern (short trips, low speed, frequent stops) does not provide the load and EGT needed for passive or active DPF regeneration. Filter loading rises until limit reached.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
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.
- Short-trip operationCommon
Parts involved
- DPF B1
P246B 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.