Audi Phone Connection Issues & Electrical Fault Fix

Had a very similar connectivity malfunction on my 2006 Audi S6 last year. Have some experience working on basic electrical issues, but this one required professional help. The ignition system would sometimes interfere with the infotainment connection. After several failed attempts to reset and repair by myself, I took it to a workshop. They found that the Bluetooth control module needed a complete reset and reprogramming. The system was storing old device data that was causing conflicts. The fix was relatively straightforward, they cleared all stored devices, performed a hard reset of the module, and properly repaired the pairing system. Total cost was 45 Euro for the diagnostic and reprogramming work. Before suggesting more specific solutions, could you share: Are there any other electrical issues showing up? Does the system still detect devices but fails to connect, or is it completely unresponsive? Have you tried clearing all paired devices from both your phone and car settings? What error codes specifically appear in the system? This information would help determine if your issue matches what I experienced with my S6 or if the fuel system or other components might be affecting the electronics.

Last service was at 142000 KM and the drivetrain diagnostics showed no issues back then. After the electrical system malfunction started, all stored devices were cleared from both car and phone. Still getting multiple error codes in the system. The infotainment stays completely unresponsive most of the time, and when it does work, it drops connection within seconds. Tried three different phones with the same result. Main error code is U0101 which points to lost communication with transmission control module, though not sure how this connects to the bluetooth issues. Steering and suspension functions work normally, but dash occasionally shows unusual warning lights. Wondering if this could be a general electrical system problem rather than just the infotainment module.

Having gone through this with my S6, those symptoms sound very familiar, especially the unusual warning lights and U0101 code. The transmission control module communication error actually makes sense in this context. The root issue in both our cases points to a failing CAN bus system that connects various control modules. When the CAN bus malfunctions, it can trigger transmission error codes and cause communication problems across multiple systems, including the infotainment. After my initial post about the Bluetooth reset fixing the issue, I discovered the problem came back within weeks. The permanent fix required: Replacing corroded CAN bus wiring, Installing a new gateway module, Updating transmission control module software Total repair ended up at 680 Euro, significantly more than the initial Bluetooth reprogramming attempt, but it resolved all issues: No more unusual warning lights, Stable infotainment connection, Clear communication between transmission control and other modules, No more stored error codes Based on the matching symptoms, I suggest having the CAN bus system checked. The transmission malfunction code is likely a symptom rather than the cause, just as it was in my case.

Thanks for the detailed follow up about the CAN bus system. That definitely explains the connection between the transmission control module error and bluetooth issues. Honestly concerned about the repair cost you mentioned, but at least it gives me a realistic picture of what to expect. My drivetrain has been solid until now, so hoping the wiring is the main culprit and not deeper electrical faults in multiple systems. Unusual warning lights are getting more frequent though, which matches what you experienced with your CAN bus problem. Will get it checked at the workshop this week, focusing on the complete electrical system rather than just the infotainment malfunction. Better to fix everything properly than keep trying temporary solutions. Thanks for helping me understand the bigger picture here, saved me from wasting time on basic bluetooth troubleshooting when the issue clearly runs deeper.