SQ8 Emergency Call System Failure Causes Multiple Alerts

I had a very similar issue with my 2019 Q8 55 TFSI last year and understand your concern about the warning lights. Having some experience with Audi electrical systems, I can share what worked in my case. The diagnostic codes pointed to a faulty connection in the telematics control module. After attempting a system reset which did not resolve the issue, I took it to a workshop. They found that one of the main cable connectors to the emergency call module was loose and showing signs of corrosion. The repair involved cleaning the connection points and replacing the damaged plug. Total cost was 95 Euro for parts and labor. Since then, the SOS signal system has worked flawlessly with no more warning lights. To help troubleshoot your specific case, could you share: Which exact warning messages are you seeing? Have you tried performing a system reset? Did the issue start suddenly or develop gradually? Were there any recent repairs or modifications to the car? This information would help determine if your issue matches what I experienced or if it might be something different in the emergency call system.

Thanks for the detailed response. The warning messages point to SOS emergency call failure and communication error with module B684. At 29170 KM and last service done 2 months ago, these automotive electronics issues are quite frustrating. The system reset was attempted but did not resolve the car safety warnings. The issue started suddenly after a heavy rainstorm, which makes me suspect potential water ingress affecting the module connections. There have been no recent modifications or repairs other than routine maintenance. Your experience with the connector issue seems very similar. Did your workshop mention any specific diagnostic steps they took before finding the corroded connection in the emergency call system?

Thanks for the additional details. Your situation sounds almost identical to what I experienced, especially with the timing after rainfall. The B684 module malfunction was exactly the same error code I encountered. In my case, the workshop ran a full diagnostic scan which revealed communication errors between multiple control units. The key diagnostic step was testing signal transmission through the entire emergency call system wiring harness. This specifically identified the connection problem near the roof antenna area. Given your car also showed issues after rain exposure, there is likely water infiltration at a similar point. My technician explained that moisture tends to collect in that area, gradually causing connector corrosion and leading to SOS signal failures. The diagnostic process in my repair took about an hour before they pinpointed the exact location. They then had to remove some interior trim panels to access and repair the affected connection points in the car safety system. Based on the matching symptoms and circumstances, I would suggest having them check: Roof antenna connections, Module mounting points for water damage, Wiring harness condition in the headliner area The repair should be relatively straightforward if they find similar connection issues. Just ensure they properly seal any potential water entry points to prevent future problems with the emergency call function.

Appreciate the thorough information about your similar repair experience. The matching symptoms after rainfall and identical B684 module malfunction definitely point toward a similar connector issue in my SQ8. Will schedule a workshop visit this week and ask them to focus on checking those specific areas you mentioned, especially the roof antenna connections and potential water entry points around the emergency call system components. The diagnostic codes showing communication errors between control units align perfectly with what you described. Good to know the repair was straightforward in your case. At 29170 KM, this kind of system failure is annoying, but at least it seems to be a known issue with a clear fix. The call failure warnings have been concerning, so having a concrete direction for the technicians to investigate will be helpful. Will make sure they check all the wiring harness connections and properly seal everything after the repair to prevent future malfunctions. Thanks for sharing your experience, it helps narrow down the diagnostic process considerably.