2014 C4 Picasso EHDI115 - Keyless FOB will not pair in Diagbox

[karbo]

Hi, I have a 2014 C4 Picasso EHDI115 with a keyless STOP/START button feature. The thing is, that I bought it with only one remote key. I did not get any spare key. But as I own a diagbox and I paired many keys with my older Citroen cars, I decided to buy one key from ebay. I was sold a brand new key. When I got it and I went straight to Diagbox and I tried to pair the new key as I used to with my old cars.
I entered the correct PIN, I wanted to pair two keys (original and the new one) and I started the procedure. The original was paired without problem, but the new one is giving me "Electronic key not present" fail.
I read a few threads and found out, that it may not be completely compatible, so went ahead and bought an original USED Citroen key again form ebay. It is totally the same key, with the same PCB and all writing is the same as my original. But now the diagbox gives me "Failure of the programming of the electronic key or electronic key identifier not valid".
I am lost. Is there any way how to programme any of the new keys or I just threw my money out of window for nothing?

[GiveMeABreak]

Because you can't programme a USED fob. The chips inside are designed to be paired to one vehicle. Once it is paired that's it. Get your money back.

[Paul-R]

What version of Diagbox are you running? If it's too early then it might not be able to recognise all equipment fitted.

[GiveMeABreak]

He's already coded his original fob successfully in the first session described Paul, it's the second hand one he bought that won't cut the mustard and the next one was a used original that can't be recoded.

[karbo]

Thank you very much for your replies. I did not have any idea that this new "keyless" key, once it is paired, cannot be used with another car.
So is there any way how to "virginize" the key? Replacing the chip? Any tips? What about the first new key I got from ebay? They claim to be the virgin key but it is not recognized by the car. Is there any way to get it to recognize it?
Do you have any tips (ebay?) on a key that will work?

[GiveMeABreak]

I can't advise on third party fobs - they are so priced for a reason... You'll need to contact the seller.

[wheeler]

So is there any way how to "virginize" the key? Replacing the chip? Any tips?

There are tools that can virginize these (genuine) fobs but probably not worth it to do one key.
There are 2 types of chips in these, ID46 or ID4A. Do you know if you have the right type?
I’ve not found good aftermarket prox/slot in keys yet for these yet, they aint very good im afraid.