Fluence alarm siren fault

Wow, that sounds familiar! I had almost the exact same problem with my old Opel Astra, although it was a few years older. The alarm would randomly go off, or sometimes not arm at all. Drove me nuts! I eventually traced it to a dodgy connection somewhere near the siren itself. Did you check the voltage reaching the siren unit? Is the siren connector corroded?

Thanks for the info. You mention checking the voltage and looking for corrosion. Any specific pins or locations where you found the issue? Also, was the error code similar to what I described?

Honestly, I didn't get that deep into it myself. I checked the main connector block for obvious corrosion and loose pins and sprayed it with contact cleaner. I'm no mechanic. But my issue was similar, yes - 'alarm system malfunction' was the gist of it. After fiddling around it worked for a while, but then failed again. Eventually, I caved and took it to a workshop. They sorted it quickly. I think you should do the same.

I appreciate you sharing your experience. I've decided to take the vehicle to a workshop for a professional diagnosis and repair. The estimated cost is around 95€, which seems reasonable considering the potential complexity. Thanks again for your advice.