I have a 98 540 with Bosch a M5.2.1 DME. I did some searching, but not much action on this DME. Has anyone worked on these? Looking for some help getting started on tuning it.
i have tuned this ecu before but not with tunerpro so i dont have a proper XDF for it, if you only need a tune i can send you one for free but if you are looking to tune it yourself !!! it will be hard good luck.