Thanks. I have already tried both USB ports the car has, and I reset/removed the connection several times.
Often, not always, the phone automatically switches from USB file transfer to charging mode. However, sometimes the car seems to register the phone as mass media device and says, there are no files.
But most of the time, the car just tells that no connection could be established and lists the phone as device “KERA-QRD_SN:5A1774DB” to which it is not connected.
