Diesel Particulate Filter Efficiency Below Threshold Bank 2
The diesel particulate filter (DPF) on bank 2 is not filtering exhaust soot efficiently enough to meet manufacturer standards. This code indicates the DPF regeneration process may not be working properly, allowing excessive particulate matter to pass through the filter.
What You Might Notice
- Check engine light illuminated
- Decreased fuel economy
- Engine running in reduced power/limp mode
- Excessive exhaust smoke or soot discharge
- Check engine light flashing during DPF regeneration attempts
Most Common Causes
- 1
Clogged or saturated DPF
The diesel particulate filter has accumulated excessive soot and is not regenerating properly, reducing filtration efficiency below acceptable thresholds.
- 2
Failed DPF regeneration process
The engine management system cannot initiate or complete proper DPF regeneration to burn off accumulated soot, often due to incomplete combustion or low exhaust temperatures.
- 3
Faulty DPF pressure sensor
The differential pressure sensor that monitors DPF saturation is sending incorrect signals to the engine control module, preventing accurate regeneration cycles.
- 4
Fuel quality or engine oil issues
Low-quality diesel fuel or incorrect engine oil can increase soot formation and reduce DPF regeneration efficiency.
How to Diagnose It
- 1
Check Clogged or saturated DPF — The diesel particulate filter has accumulated excessive soot and is not regenerating properly, reducing filtration efficiency below acceptable thresholds.
- 2
Check Failed DPF regeneration process — The engine management system cannot initiate or complete proper DPF regeneration to burn off accumulated soot, often due to incomplete combustion or low exhaust temperatures.
- 3
Check Faulty DPF pressure sensor — The differential pressure sensor that monitors DPF saturation is sending incorrect signals to the engine control module, preventing accurate regeneration cycles.
- 4
Check Fuel quality or engine oil issues — Low-quality diesel fuel or incorrect engine oil can increase soot formation and reduce DPF regeneration efficiency.
How to Fix It
- 1
Perform forced DPF regeneration
Use diagnostic scanner to initiate a forced regeneration cycle on bank 2, allowing the engine to raise exhaust temperatures to burn off accumulated soot.
- 2
Clean or replace diesel particulate filter
Remove and professionally clean the DPF unit, or replace it if cleaning does not restore efficiency. This is the most common repair for this code.
- 3
Replace DPF pressure/differential sensor
Test and replace the DPF pressure sensor if it is sending incorrect readings that prevent proper regeneration cycles.
- 4
Check fuel quality and perform engine maintenance
Verify high-quality diesel fuel is being used, change engine oil and filter, and check fuel injectors for proper atomization to reduce soot formation.
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