EGR fault code P040100

I connect ODIS to the car from time to time as a routine check up. I was surprised to see the following error:

Examining my exhaust pipe there was a lot of black soot deposited. I thought that something is wrong with the DPF and soot is directed to the EGR causing the P040100 error to appear. But if the DPF is full, shouldn't there be a warning light in the dashboard? Of course yes, unless there are small cracks inside the DPF which let soot go to EGR as well as to the exhaust. And yes, my exhaust is black from soot…

I arranged a meeting at the dealership feeling worried. I showed them the above screenshot from ODIS. They performed guided fault finding and, to cut the long story short, I was right: my DPF seems to malfunction. After performing a forced DPF regeneration the error went away. The car was driven by the technician 33 km and thankfully the error did not reappear. But they were not very optimistic. I was also told that if the error comes back, the VW official advice is to replace the DPF filter.

That was bad news…I know replacing DPF is costly and the dealership confirmed that: 2000€ + 24% tax + labour costs. Cleaning the DPF they did not suggest as their experience says that even after cleaning, sooner or later you will need the DPF replacement.