The new style (diamond shaped) keys are sealed. Thus to separate the two halves requires a tool that can cut thru the seal...and a butterknife is not the tool for that. You need something like an X-Acto knive or razor or utility knive...something SHARP.
You also need to be very careful because if you gouge too far into the key case...you can also damage some of the small stuff on the IC board inside the key...or damage the coil and/or antenna which is also attached to the IC board. Damaging these small things can ultimately render the key or some of it's functions useless.
There are 3 features/systems designed into the remote key...all separate but work in conjunction with each other:
- EWS - immobilizing system
- FZV - central locking system
- DWA - anti-theft alarm siren system
You will also need something to reseal the key once you have cut it open...there is no mechanism that will keep the two halves together once the key has been separated into two halves.
Just to clarify the INCORRECT information in post #2 (which is from way back in 2009)...the first instructions are actually correct BUT does NOT require a working key and a new unprogrammed key...thus the "alternate" instructions where you have to turn the key FIVE times in the ignition is probably unnecessary.
See the instruction below from BMW...and not instructions that have been floated around the internet for decades that have been altered as it's been written and rewritten many times over.
The important thing is...if you have multiple remote keys...ALL of them must be present when you reinitialize...because the remote key that is not present and not reprogrammed...will
NO LONGER lock/unlock &
arm/disarm your vehicle (until you reprogram ALL of your remotes in the same session).
