Its just a reminder so you can visit the dealership. They will inspect your pad lining and if they are worn/out of specs they will sell you a brake job. If pads linings are in good condition they will just turn off the reminder light. I have over 80k and have about 70% front and 30% rears, I turned off the reminder with the control stalk. Theres a DIY for that in here or on youtube.
btw....Alen E90 is the e90post angel, just sayin: