Particulate Filter Restriction Ash Accumulation Bank 1
The particulate filter burns off soot, but the ash left by the oil does not burn: it builds up over the kilometres until the filter is full.
What the car has detected
The ECU works out that the filter holds so much ash, or is so restricted, that regenerations can no longer clean it.
The car usually goes into limp mode. A badly restricted filter raises exhaust back-pressure and can damage the turbo, so drive gently and have it checked soon.
Symptoms
- Engine or DPF warning light on
- Loss of power or limp mode
Possible causes
- Ash built up over high mileage
- Wrong engine oil or oil burning
- Damaged particulate filter
- Software that does not match the filter fitted
Checks for the garage
- Read the ash and soot load with the diagnostic tool
- Check the differential pressure sensor and its pipes
- Run a service regeneration if the garage thinks it possible
Next step
Ask for the filter’s ash and soot load to be read: it may need a professional clean or replacing.
Go to a garage soon. After replacing or cleaning the filter it must be registered in the ECU with a diagnostic tool.