re-coding a 197 and it's key

Does anybody know what is involved in 're-coding' a 197 and it's key?

I have only got 1 key, and the dealers have said that they re-coded the car and key so that the 2nd key (MIA) will no longer operate the car. I was under the impression that this required some hardware swapping and new keys? Any info on this would be great lads! :smiley:
 
When u loose a key or sumin you bug a new card, which is "blank" regardin coding. U then have to get the card programed to the car :smile: