On traveling home from Aviemore yesterday, a 90 miles journey. I stopped of at Inverness for a 1 hour or so, then continued home at 50 to 55 Mph. When parking up I could here the fan running and I became aware of a burning smell. When I switched of the fan continued to run for a few minutes. I am now wondering if I had interrupted a regeneration cycle. Is this likely to be right ? The Fiat Ducato van has 5000 miles on the clock.