I'm here to tell you that I solved it, it was the ground cable that wasn't making good contact with the chassis. Retrofit complete, I just have one question, I don't have the setting to vibrate the steering wheel, is it because my car isn't set up for this or did I skip some steps? This function seems to be in bit 13. I tried to enable both the vibration via the menu but also by setting it to active the steering wheel does not shake.
@Cuzoe I live in Polignano a mare not far away