What do the Key Fob numbers mean?
 

I am trying to make a 2nd key and have noticed that there are a bunch of numbers written on it:


FCC ID: MYT 4073A
IC 4427A-4073A
06.569.800 16S
8E0 837 220 R
315 MHz (frequency of chip?)


So I have a few questions:

1. Can anyone explain what each number means?
   
2. Also, I understand that, to cut a new key, the most important of them all is the "FCC ID"? If so, why?
   
3. I've also read that some buy used, already cut keys, which they then program at the dealer - but doesn't the cutting pattern need to be exactly the same to be able to work? All the B7 keys I've seen thus far all have slightly different cutting patterns

Thx

Re: What do the Key Fob numbers mean?
 

1) FCC ID = Federal Communications Commision Identification #
The next two numbers are your imobilizer and programing codes
8E0 = Audi Part #
Frequency that the remote operates on

2) FCC ID to my knowledge is not used for programing (anyone please correct me if I am wrong)
3) Used keys do get bought all the time but are the blade is replaced and re-cut to match the current key. Certain Audi dealers will not cut the key unless you purchesed it from another Audi dealer or them as their machines are known to break down if the material is not the same as OEM. More brittle etc.

Re: What do the Key Fob numbers mean?
 

There are vendors that sell a pre-cut key and tell you that as long as the numbers match, all you need to do is re-program @ dealer...can it be that one of the numbers on the key determines the cutting pattern?