What happens when you loose one of your key remotes to a push button engine

Nothing you can do,accept go to dealer,and have security code changed,but the likely hood of a person that find,s your key,can find your car,but that said,if you think you may have lost it where you were seen and i mean with car to,should be safe,but it,s all up to you ,,good luck with it.

tst is wrong i am sorry to say. You need to go to the BMW dealer with all your keys left, they will check for the remaining keys in the module memory and erase the key that got stolen and the car would not start anymore with that key. The only part were TST is right is that the mechanical key can open the car, but can not start it.

Hector,i think that,s what i said,