Sony Car Stereo with USB socket will not recognise my iPhone 6?

My Sony car stereo with a USB will not recognise my iPhone 6?

I live in England and I have a Sony CDX-G1000U car stereo which I bought because it has a USB socket in the front to connect my iPhone 6 for music playback and charging.

When I plug my iPhone 6 in I get a "USB NO SUPPORT" message and the phone will also not even charge?

I have tried to read up on this problem on the internet and while there is much talk of ios 9 issues and problems with the apple cable I am yet to fully understand why my music will not play through the USB socket and what, if any, options I have to get around this problem and get it to work?

Can anyone explain to me why this is not working?