I have two Mini keys for my 2004 R53. One works perfectly in that it starts the car and actuates the door locks. The other starts the car but does not actuate the door locks. Both keys contain a transponder chip. The working key has a tag on the circuit board that reads 3D760BA 17/06/04. The lock non-working key tag reads 3FAC55 18/06/07. When I remove the circuit board from the non-working key and push the lock and unlock buttons there is a tiny light on the board that activates in both cases. Should the tags inside the keys match? Will getting the non-working key require programming of some sort and, if so, what program should be used? I have access to a very expensive Autel scanner but I'm not proficient with it. Would this be a device that might fix the key issue? Thanks.

 

In my experience, with facelift models, the only thing that need to match is the band mhz. You can buy an AliExpress key, do the learning procedure and it will open and close the doors.

The transponder is only there for the ignition.

 

It's my understanding that the only introductory facelift models in the year 2004 were the convertibles. My MC40 is definitely not a facelift version. I did swap a facelift MS5150 ECU into it as it has more tuning capability than the pre-facelift EMS2000. I'm not sure having the newer ECU would make a difference with the keys or not. I do find it strange that one of my keys operates the door locks but the other does not when both start the car. I tried the learning procedure multiple times with no success.

 

I am not 100% sure but I believe only the facelift keyfob can be synced to the car without coding them.

I bought a new key when I got the key and the mechanic asked anither mechanic if this keyfob was the BMW E46 style or not. Later I found out that this is the difference between pre and facelift models. The early keyfobs are from the (land) rover era. I believe most refer to the early keyfobs as teo button style where the facelift have the 3 button style.

I have this site in my bookmarks which may shed some light on your style of keyfob. Hope it helps.

 

Thanks much for the link. Interesting information, for sure, but coding is beyond my capabilities. I will, however, try the second key initialization procedure since the first didn't work for me. More later.