Sylphy Anti-Theft Alarm Issue

That sounds familiar. I had a similar issue with my 2016 Opel Astra. The alarm system would just randomly throw errors. It turned out that the alarm was coded to activate the optical locking, you know, make the indicators blink when locking/unlocking. What happens when you lock/unlock the car? Do the blinkers work?

Interesting. You mean the indicator lights could be the culprit? When I lock or unlock, the blinkers don't work at all; now that you mention it, I am not sure when they stopped working! Is there a way to check this optical locking setting?

Yeah, on my Astra, the blinkers were the issue. I couldn't check the setting myself. A workshop had to reconfigure the alarm control unit. Cost me 45€, a real steal! If the blinkers don't work either, that's where I'd put my money.

Turns out you were spot on! Took it to the workshop, and it turns out the alarm system was indeed coded incorrectly, trying to trigger the blinkers but failing. They recoded it, and everything's back to normal, including the blinkers when locking. 45€ later, problem solved. Thanks for the help!