The speaker that isn't functioning properly is the center speaker, just above the center air vents and below the radio display (photo attached). The strange thing is that the speaker doesn't function with Bluetooth phone calls only. Everything else using Bluetooth audio (ITunes, podcast, streaming from internet, etc.) work just fine. Any ideas??

 

I’d like to pose this problem again, because I’m experiencing the same exact issue. I have an iPhone 10, and have never gotten the main center speaker to work with my Bluetooth TELEPHONE audio. Music and videos are fine. I’ve swapped out the Bluetooth module, but no change. Any thoughts?