I believe the auto lock is one of the functions programmed into the key memory. You will have to take it to someone (dealer) that can reprogram your keys/X5. Take a look at the main X5 page under “miscellaneous” and you’ll find a couple of links for key memory programming.

I looked at updating the memory features at one time and found it can be expansive if you have a lot to change because of the man hours. I was told by the dealer that each function had to be reprogrammed by itself, taking 5 to 15 minutes each. At some point I am going to go to another dealer to verify the info from the first dealer.