2014 BMW 118d SE - USB Connectivity

[KenJ]

Hi all,

We picked up our new (to us) 2014 BMW 118d SE this afternoon - have managed to pair our iPhone's via Bluetooth to make and receive call no problem.

However, when I plug either my iPhone 6 or my wife's iPhone 5 via the USB under the armrest the car doesn't seem to connect to allow us to play music. The phone starts charging, but I can't select the USB, the iDrive just has a blanked out "not connected." We're connecting via a lightening cable

Does anyone have any ideas why we can't play music through the USB?

Any help appreciated.

Thanks