P226D
Particulate Filter Deteriorated/Missing Substrate (Bank 1)
The DPF substrate on bank 1 has been detected as cracked, melted, or removed. Differential pressure across the filter is too low for the measured exhaust flow — the soot trap no longer works.
- 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.
- Substrate cracked or melted from runaway regenCommon
- Substrate removed by tamperingPossible
Parts involved
- Diesel Particulate Filter
- DPF Differential Pressure Sensor
P226D 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.