P2003Powertrain
Powertrain · SAE
Particulate Filter Efficiency Below Threshold — Bank 2
Meaning
The diesel particulate filter (DPF) on bank 2 is not trapping soot particles with the required efficiency. The ECU detects, via the differential pressure sensor, that the filter is not building the expected back-pressure or that regeneration is not reducing particulate matter sufficiently.
Common causes
- Physically damaged DPF (cracked or melted substrate) allowing particles to pass through
- DPF clogged beyond regeneration capacity (non-combustible ash accumulation)
- Active or passive regeneration impossible due to excessively short driving cycles
- Defective DPF differential pressure sensor or blocked pressure lines
- Faulty post-injection injector preventing active regeneration
- Incorrect engine oil (excessive SAPS content) accelerating ash fouling
Symptoms
- DPF or check engine warning light on
- Power reduction (limp mode activated)
- Increased fuel consumption
- Burning smell or black smoke from the exhaust
- Failed or very frequent forced regeneration attempts
Severity
High: an inefficient DPF causes high emissions, possible damage to the downstream SCR catalyst, and if unresolved may require filter or engine replacement.
What to do
- Check DPF differential pressure with a scan tool (compare with ECU map values)
- Perform a forced regeneration via scan tool; if it fails, consider professional DPF cleaning
- Inspect the differential pressure sensor and lines for blockages or leaks
- Check the post-injection injector and active regeneration system
- If the DPF substrate is compromised, replace the filter