as far as i know there is no procede for m3. i am using the same maps on my 11 335is dct so seems like something install or hardware related
are you sure all of the connectors on the harness are facing the proper directions?
2015 MW/SO M4 M-DCT [CURRENT]
2011 AW/CR 335is DCT FBO [SOLD]
2008 AW/CR 335i 6MT FBO [SOLD]