VW Bora Alarm Module Failure, Owner Seeks Fix

I had a really similar issue with my 2002 VW Golf back when the immobilizer and alarm sensor started acting up. As someone with some hands-on experience working on VWs, I can share what worked in my case. The alarm system on these models can get glitchy when the control module loses its programming. In my case, the anti-theft system needed recoding because the module had defaulted to factory settings. The main symptom was exactly what you describe, a completely dead alarm system with no false alarm notifications. Took it to an independent workshop specializing in VW electronics. They diagnosed and reprogrammed the alarm system, specifically the optical locking sequence for the indicators. Total cost was 45€ for the programming work. Much cheaper than replacing the whole module. Before jumping to conclusions though, could you share: Does your key fob still work for locking/unlocking? Are there any other electrical issues? Have you checked if the battery in the alarm sensor is still good? Did you notice any warning lights on the dash before this happened? These details would help determine if your issue matches what I experienced or if you might be dealing with something different.

Last service done at 119691km. Thanks for the responses so far. The key fob still works fine for locking/unlocking but no visual confirmation from the indicators anymore. No other electrical issues noticed and the battery in the alarm sensor appears fine based on voltage testing. The immobilizer functions normally, just the alarm system itself seems completely dead. Interesting point about the module losing programming. Seems that could match my symptoms since the false alarm feature and all alarm functions stopped working simultaneously rather than gradually failing. No warning lights appeared on the dash before or after the system died. 45€ for reprogramming sounds way better than a full module replacement. Will try finding a shop that can diagnose and recode the alarm control module first.

Good to hear your immobilizer is still working normally. Based on what you are describing, it sounds exactly like what I experienced with my Golf, especially the part about the indicators not giving visual confirmation and the sudden complete system failure rather than gradual issues. The symptoms really point to a programming issue rather than a hardware failure in the anti-theft system. Since there are no other electrical problems and the battery tests fine, I would be confident recommending the reprogramming route first. When my alarm system failed, the shop also checked the wiring connections at the control module as part of their diagnostic process. In some cases, corroded contacts can cause the module to lose its programming. They cleaned the connections before recoding, which might have helped prevent the issue from recurring. One thing I forgot to mention, after the fix, they recommended checking if the car alarm works properly by doing a full system test. This helped confirm the programming took correctly and all alarm functions were restored, including the false alarm notifications. Have you already found a workshop that specializes in VW security systems? Make sure they have experience with these specific alarm modules, as not all shops have the right diagnostic equipment for recoding them.

Thanks everyone for the suggestions. I will definitely try the reprogramming route first before replacing any parts. My situation matches the programming loss scenario perfectly, especially with the instant failure of all alarm functions and the indicators not responding. Just called around and found a specialist workshop that handles VW alarm system diagnostics and programming. They quoted 50€ for diagnostic and recoding work, which seems reasonable compared to module replacement costs. Have booked it in for next week. They mentioned they will clean all the control module connections and do a full alarm system test after reprogramming to make sure everything works properly again. Really hoping this resolves the issue since I was worried about having to replace the whole security system. Will update once I get it sorted to let others know if reprogramming fixed these symptoms. The identical experiences shared here with sudden alarm system failures and successful recoding gave me confidence to try this approach first.