Matrix Anti-Theft Alarm Malfunction

Hmm, that's a tricky one. Have you checked the battery recently? A weak battery can sometimes cause weird issues with the security system. Also, does the immobilizer seem to be working correctly? Sometimes, if the system thinks the car is being stolen, it can disable things or throw errors. Is it possible the alarm is coded to activate the hazard lights/indicators and there is an electrical issue that's causing the alarm to think there is an optical locking problem? Have you verified all door and hood sensors work?

The battery seems fine, and the immobilizer appears to be functioning as expected. The indicators do flash a lot. Could the optical locking being the issue really be the problem? Is there an easy way to disable that myself?

It definitely sounds like the optical locking function could be the culprit. Unfortunately, disabling it yourself isn't straightforward, as it usually requires reprogramming the system. You could try disconnecting the battery for a bit to see if that resets anything but, honestly, your best bet is to take it to a workshop. They can diagnose the issue and reprogram the alarm system. It shouldn't be too expensive, and at least you'll have peace of mind knowing it's fixed properly.

Thank you for the information. I took it to a workshop, and it turned out the alarm system was indeed coded to activate the indicators, causing the malfunction. Recoding the system cost 45€, and it's now resolved.