Key battery replacement question
 

Hi all. I've read all the posts regarding this topic and am ready to do the DIY key battery replacment. There is one thing I'm not sure of though.

At the moment, I only have one key (it only came with one from the used car dealer). I have successfully reprogrammed the keyless entry a few times using the one-key method so I know this part of the process works. However, if I remove the battery and replace it with a fresh one, will the transponder still allow me to start the car after it has been isolated from a power source? I'm not sure whether removing power for a short time from the transponder unit in the key will result in a non-functioning key.

If anyone could clarify whether the transponder will continue to function correctly after the battery replacement, I would feel much more comfortable about going ahead with this.

Thanks

I replaced the battery in one of my keys and it still started the car but could not reprogram it to lock unlock the doors.

If you have another vehicle that you can drive do yourself a favor and send your key to the guy in the link below. I just had my key repaired buy him last week and it works better than new, it only costs $55!

BMW General Module 5 (GMV, ZKE V)