Ford GT anti theft alarm malfunction

I had a similar problem with my GT. Does the error memory relate to the immobilizer, perhaps? My alarm was going off randomly. Could be that your alarm system is coded to activate optical locking, meaning the indicators flash when it arms. This can sometimes cause issues.

Optical locking? I'm not familiar with that term. Could you explain that a bit more? And was the immobilizer the cause of your false alarm?

Yes, optical locking means the turn signals flash when you lock the car. It's a feature some cars have. In my case, I ended up taking it to a workshop. They said that the alarm was triggering due to some weird setting related to that. They recoded some settings and that fixed it.

Thank you for the tip! I took it to the workshop, and you were spot on. The alarm system was indeed coded to activate optical locking, which was causing the issue. Recoding it cost me 45€ and solved the problem!