VW Polo Bluetooth Mic Failure, Troubleshooting Guide

I had a nearly identical issue with my VW Golf from 2002. As someone with moderate experience working on cars, I first thought it was just a simple Bluetooth issue, but it turned out to be more complex. After basic troubleshooting failed, I discovered the audio system had a faulty control module affecting both the voice recognition and volume control functionality. The microphone itself was fine, but the system wasnt processing any input. The workshop diagnosed it as a defective infotainment control unit. Total repair cost was 815€, which included: New control module, Programming/coding, System testing The repair resolved all issues: Bluetooth connection stability, Speech recognition functionality, Microphone operation, Overall audio system performance Before suggesting specific solutions, could you share: Have you checked if the microphone works with other phone functions? Does the voice control fail for all commands or just during calls? Are there any other audio system issues besides the microphone? Have you tried resetting the infotainment system? This information would help determine if youre facing the same underlying problem I encountered.

Last service was at 52000km and everything worked fine back then. Since I posted, I did some basic checks. I tested the voice control with navigation commands and that failed too, so its definitely not just affecting phone calls. The speakers work perfectly for music and radio though. I also tried reconnecting different phones but got the same result, they pair fine but no audio input works. The error code specifically points to the microphone circuit. Considering the age of the system, Im starting to think a full audio control module replacement might be needed, even though its a costly fix.

Thanks for the additional details, those symptoms match exactly what I experienced with my Golf. The fact that only the audio input is affected while output functions work normally really points to the control module issue I encountered. Like in your case, my voice recognition completely failed for both navigation and phone functions while ambient noise reduction and general audio playback remained unaffected. The working speakers but non-functional microphone was a clear indicator of the control module problem rather than a simple Bluetooth issue or loose connection. After my repair, I learned these systems often develop similar faults around the 50-60000km mark, which aligns with your timeline. The control module gradually loses its ability to process audio input signals, though other functions continue working. Based on the matching error code and identical behavior, I strongly recommend having the control module checked first rather than replacing individual components. In my repair, they initially considered just replacing the microphone, but diagnostic testing confirmed the broader control unit failure. The cost range should be similar to what I paid (around 815€), but you might want to: 1. Request a full diagnostic readout 2. Confirm if the workshop has experience with this specific audio system 3. Ask about any available upgraded control modules that might offer better longevity

Thanks for sharing those experiences. Your situation matches mine perfectly, especially the pattern of only audio input being affected while other functions keep working. Really helpful to know about the common failure point around my mileage range too. Since posting, Ive gotten quotes from two workshops. Both suggested the control module replacement, with estimates between 780-850€. They confirmed my suspicion that just replacing the microphone wouldnt solve the underlying audio system problems, especially given the complete failure of voice recognition across all functions. Think Ill proceed with the full control module replacement next week. The Bluetooth issue and complete lack of audio input make the car really impractical for work calls. Plus the wireless connection problems are getting worse, now it sometimes disconnects even when paired. Better to fix it properly than try cheaper partial solutions that might not work. Will update once the repair is done in case anyone else runs into similar sound quality problems with their VW audio system.