You have to have a chip in the key then have it cut to your other key then go into the modes on the dash menu w/your user code. It should be in your manual on how to. Been a few years since I did one. I can look it up.
1) if one key is lost; the dealer can disable this key;
2) to activate up to 4 keys;
3) should a new key lock be necessary and thus program the new set of keys.
In the first phase the user code must be entered and, after confirming the inserted key (key I) has been
programmed, the other keys must be entered too.
The procedure finishes once the 4 keys have been programmed or after 20 seconds.
Should a new key lock be necessary, the procedure is: once the key is set to ON but the instrument
panel does not recognise it, the user code is requested: enter the user code.
Now enter MENU, DIAGNOSIS (entering the service code), KEY CHANGE and program the new keys.
If this is confusing I can simplify. Read This--[You must be registered and logged in to see this link.]
I think the code on the spare tag gets you one cut the same as what you have but you still need to program them all the same. Pete will know for sure.