Hello all,

Among the plethora of threads about this issue I present my situation. I have an 05 MCS with chrono pack and the second generation key (3 button). First item I replaced/switched was the rear view mirror which did not fix the problem. Second was I replaced the battery in the key itself and that did not work. Third I purchased an aftermarket key (same style) and swapped shells and transponder chip. Car would start but I could not code and again, it did not work. Finally I purchased a BMW flip key and had the blade cut to the car. I bought an AX90 and coded the key to the car. The lock opens the door and the car starts no problem, however, coding sequence for the car is still a no go. I'm at a loss as to where to go next, everything I've tried hasn't worked and I don't know where to dig around in the car next to fix it. I've swapped the original and new mirror also while attempting to go through the lock sequence with the new key. Something else in the car is not working and I have no clue what it is.

Stay safe out there friends