I had this, even started a thread on it and commented on others. Tried updating i-drive software but that didn't work, car failed to read the usb so I gave up intending to visit dealer.
Then, about a week ago, it healed itself
Mine was iPhone 5 (os 10.1.1) - incoming calls from
some mobiles but not all connected, but neither party could hear the other. Silence, no background noise, but call time ticking away so still connected. Everything else as normal i.e. outgoing and land line calls fine.
Still no flippin idea what went on. Seems ok now but if you get to the bottom of it please post as I'm sure it'll happen again.
