EQV Anti Theft Alarm System Malfunction

That sounds frustrating! Was it throwing any false alarms before failing completely? Maybe a dodgy door switch or hood sensor is triggering it initially before the system shuts itself down. Have you checked for any obvious signs of tampering around the car alarm components?

There were no false alarms preceding the complete failure. The system simply ceased functioning, and the error code appeared during a diagnostic scan. Is there a straightforward method for testing the door switch or hood alarm sensor to ascertain their functionality?

No false alarms beforehand changes things. Testing those sensors properly usually needs diagnostic equipment to read their status. Given the error code and no prior false alarms, it does sound like a coding issue as you initially suspected. A workshop visit is the best bet.

The issue stemmed from the alarm system being incorrectly coded to activate optical locking. The repair cost amounted to 45€. Thank you for pointing me in the right direction.