I have a 2006 M45 sport. I purchased the car with one aftermarket key fob that only starts and unlocks/locks the car manually. I had a locksmith come out and was told that the aftermarket key fob would not work. The aftermarket will only do what it can currently. I purchased an OEM KEY FOB, the same locksmith is telling me that it can’t be programmed because the ID sticker on the driver side door has a manufacture date of 12/04. He says his program goes from 2006-2010. He thinks that programming the key fob using the 2096-2010 program may not work and will essentially erase the current aftermarket key and I will be left with no operable key. I never realized how much I want and need my remote buttons, please help. Thanks.

key fobs are one thing you should go to the dealer for. Don't try to do it yourself or you will screw it all up. I went through this myself and despite many programmers saying they will do it, you only get the most basic functionality like manual lock/unlock and the ability to start the car, same as your aftermarket one. You MUST go to the dealer to make everything work properly. You also cannot just buy an OEM key off ebay, that usually won't work as you must match certain IDs together to ensure compatibility.

I programmed the key fob, but that doesn't seem to be the issue. I was reading that if you jump the battery the wrong way you can blow somethings, one being the BCM. The key fob is programmed, it transmits a signal. The car has a new battery and I am thinking the previous owner jumped the car incorrectly and blew the BCM. I've ready that if it is BCM, that would have to be programmed to car and key fobs reprogrammed. Anyone have any insight on this type of issue? Thanks.