Does anyone know how to reprogram a dead key fob on a 2004 325xi? It is my never used spare key. The dealership tried to reprogram it, but could not and suggested I use it when driving in an attemt to "charge" it. Then if it
holds the charge, it could be reprogrammed. The person who attempted the
reprogram followed some kind of sequence. It seemed straight forward enough, so
I was hoping if the key can get recharged, then I can reprogram (or synchronize) it myself. Thanks.

I would like to know too. Just bought a 2000 323it for my wife last week and one of the keys is dead too.

Use search!

Duh, Its not working right now!

Yep, the keys are charged through the ignition, so they die if they sit for too long. You'll need all of the keys with you in order to initialize them. If you have car key memory preferences set, you need to know which key is key 1, 2, 3, etc. otherwise, the preferences may get assigned to different keys.

First step, get in the car and close all doors. Insert key 1 into the ignition, and turn it to the first position, then immediately off and remove the key. While holding down the unlock button, and quickly press the lock button 3 times, then release both buttons. The locks in your car should cycle to indicate that it was succesfully initialized. Once you do the first key, repeat the underlined portion of the process for the rest of the keys.

http://bimmer.roadfly.com/bmw/forums/e46/307297-1.html

Thanks guys. Hopefully the key will hold the charge and then I will follow the
sequence. I will let you know how it works out.

Worked great for me, thanks.:)

The key never held the charge, so I was prepared to pay for a new key from
the dealership. What a shocker...it was covered under warranty!