Car model and year: Audi A4 B8 2012
Purpose: to add new key
Key Programmer to use: Xtool X100 pad3
you can add it with xtool pad no problem as long as you can read BCM2 data. Check the freq of the key first.
I tried to reset with KD X2. Did not Work. Because of the freq.
I already tried to re-add my Original Key with xtool. This works.
When you get dealer key you can learn it to car with pin code and dont forget must relearn the ezisting key also.
I got Xtool Pad 3 also, did few keys with 5th immo. You can buy keys from China, There are some decent quality keys. First you will need to make a “dealer” key then you will program to the car. As long as you have 1 working key, no need to dissasembly anything as I remember . Have in mind, that if your car is with keyless entry, you need to look for keyless key, because they are more expensive and more rare.
Xtool X100 pad 3 tech support https://www.xtool.co.uk/ .