T-Roc Alarm Siren Malfunction, Wiring Fix Guide Needed

Had a similar situation with a 2019 VW Tiguan last month. The automotive alarm system showed the same symptoms, complete failure with error codes related to siren communication. The root cause was a combination of corroded wiring connections and a faulty control module near the siren unit. Vehicle security systems often develop these issues when moisture gets into the connectors over time. Main fault detection revealed two problems: Damaged wiring harness between control unit and siren, Partially failed alarm control module The repair required: 1. Complete harness replacement for the alarm circuit 2. New control module installation 3. System recalibration and alarm reset This was a serious repair as it involved removing several interior panels and reprogramming the security system. The work took about 4-5 hours to complete properly. Worth checking the connections first, look for green corrosion around the siren unit wiring. If visible, its likely spread further into the harness. These wiring issues are fairly common in VW models from that generation and usually need professional diagnostic equipment to properly resolve.

Thanks for the detailed walkthrough of your Tiguan repair. My T-Roc is showing identical issues with the alarm system and error codes. Actually got it checked today and the mechanic also found corrosion in the wiring near the siren unit, suggesting a potential security breach in the connections. Planning to get it fixed next week, but curious about your experience, what did the total repair end up costing? And has the alarm controller been working properly since the fix, or have you noticed any lingering signal problems? The parts list looks similar to what my mechanic suggested, so would be helpful to compare costs before moving forward with the repair.

Glad I could help with the initial diagnosis. The good news is I got my vehicle security system fully repaired and the siren communication fault hasnt returned since. The fault detection system shows all clear now. In my case, the fix was much simpler than initially expected. The mechanic found the main signal problem was just a loose cable connection at the siren unit. No need for the extensive repairs we first thought might be required. The total bill came to 95€, which covered cleaning the corroded connector and securing the connection properly. The automotive alarm has been working flawlessly for the past month, no more error codes or security breach warnings. Based on your description, it sounds like you might have a similar straightforward fix ahead. If its just connection issues like mine was, you shouldnt need a complete system overhaul. Definitely a relief it turned out to be a simple wiring fix rather than needing the full control module replacement we initially feared.

Just went to the mechanic today and got some good news. Like you mentioned, they found corrosion in the wiring connections near the siren unit. Turns out the main fault detection showed it was mostly surface damage, not the deep system issue I feared. Total repair came to 180€, slightly more than yours but still reasonable. They cleaned all connections, replaced one damaged section of the wiring harness, and recalibrated the vehicle security system. The alarm controller is now working perfectly and all error codes have cleared. Really glad I asked here before assuming the worst. The signal problem was much simpler to fix than expected, and now the alarm disarm function works smoothly again. Thanks for helping me avoid an unnecessary full system replacement.