Expert solution: Yes you can interchange them. 2 and 3 button remote is same inside as i know, just the button left out in some remotes. You can teach in an used electronic to another smart car. Teach in all needed keys, not only newer. Receiver of signal is outside SAM, looks like a relay with 3 terminals. Older ZEE modules (1999-2000 I think) will not accept 3 buttons key instead of original 1 button but SAM modules should. Tried many times on 2002-2004 models. Your 2001 should be ok too I guess. If your Smart remote key has 433MHZ frequency, job could be easier. If you can not find the 315MHZ 3 buttons key, you can try to rework the remote. You are at your risk. Just need to change SAW filter in it with 315MHz one. It is possible to make receiver that accepts both frequencies but I don’t think this is the case for ForTwo’s. So better buy correct 315mhz keys, they are available from China. I have tried FVDI abrites commander full version. Key has to be off when prompted (ignition off) Guided on screen. Will ask ignition on then off press button count down then done. If you have original AVDI commander, it will do 100% as well. Solved! Made the key today. AVDI works like a charm. Key job done in 30 seconds.. :-).
Problem: I have a customer whose old 2001 Smart Fortwo 450′ SAM is waterdamaged. I have read 1d69j and i´ll clone it to a donor one. No problem. Customer bought the 450 with just one key. He wants to have a second key. The remote key is the old version with one button. I cannot find this one, but a lot of keys with three buttons from the newer Smart (2004 up). Can i make a three button key for first generation of smart? BTW, It is made in German. It has VIN, not FIN (WME450…). I tested key with frequency tester: 315 MHZ. All keys on aftermarket have 433 MHZ…Where can I found Smart 3-button key with 315 MHZ or can i modify frequency from 433 MHZ to 315MHZ?