I did an extensive research, and finally enabled the car to perform a regen, with the help of Inpa K+DCAN USB cable. Checking engine temp was above 75c etc etc – no joy.
I drove 1,000km later still on and even after thrashing for miles on the motorway. I bought my e90 325d 2007 with unnervingly clean exhaust tips and shortly after having DPF warning light come on.