bmw particulate filter regeneration takes place every 300 to max 2000 km. It takes place when you drive at an average speed of 50 km/h for 20 minutes. Computer will take over and your vehicle will drive as in Sport mode. The particulate filter will heat up in order to burn everything that's stuck inside of it.
BMW diesel owners: Do you have a strong burnt smell when this particulate filter regenerates?
http://www.realoem.com/bmw/partgrp.d...43&hg=18&fg=10
http://www.bmw.com/com/en/insights/t...le_filter.html