I have a 2015 mk3 Fabia. The key broke and I managed to super glue the base as an emergency. I have a brand new spare key. But it does not start the car when I use it. There is some kind of imobilizer on, or it isn’t programmed. Please help what do I do?

I'm sure someone else will be along shortly to add more info, but yes as far as I understand the immobiliser and the radio frequency unlock work independently. I remember reading somewhere that it may be possible to code a new key if you have an existing working one with VCDS 🤔 but the proceedure in the car manual is only for syncing the RF part and will not allow you to start the car.

On 04/01/2020 at 20:10, Sydney1 said:

I have a brand new spare key. But it does not start the car when I use it. There is some kind of imobilizer on, or it isn’t programmed.

RTFM; there are instructions there for programming a new key.