USB stopped working

I have a 2010 Prius III and the USB has stopped working with our iphone 5. It has worked fine for the last six months and then out of the blue, it will not connect to the audio system or charge our phones. I took it to the dealer who said that the usb port worked with their device and cable. They recommended that I should buy a new cable. I did that, no change. I also erased my phone and re-installed the operating system. There was a brief flash when the recharging system kicked and then it immediately went back to no connection. After extensive experimentation, I found: The prius will charge my old iphone 3g with the 30 pin connector. It will play music from my ipad 2 also with a 30 pin connector. It will occasionally recognize my iphone 5 with the six pin connector for a brief moment and then stop.

I have tried new and old cords, new and old devices. I am at a loss how to proceed. I would like to get the dealer to fix it, but since they can't replicate the problem, I don't even know how to talk to them about it. Any suggestions on how I can move forward would be appreciated.

 

Thank you for the suggestion. I reinitialized a flash drive and put an mp3 file on it. The file played just fine. We have been using iphone 5s with the prius usb for six months without any problems. The issue must be in a recent software update for the phone, or perhaps a six pin connector problem, but the issues does not correspond to the 7.1 update. It happened out of the blue: One day the system worked worked, the next it did not.

 

That is a great idea. If resetting the phone sometimes works, resetting the car should as well. I will give it a try and report back.