P249F
Excessive Time To Enter Closed Loop Particulate Filter Regeneration Control
The DPF regeneration controller cannot transition into its closed-loop temperature control quickly enough - typically because EGT does not rise to setpoint within the calibrated window.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
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.
- EGT rise too slowCommon
Parts involved
- DPF B1
- Exhaust Gas Temperature Sensor B1
P249F 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.