Car stereo suddenly stopped being able to read iphone?

I have a JVC car stereo and an older iphone 3G. I was listening to my iphone's ipod music on the way to an outdoor fun day and everything worked fine. When we got back in the car to come home all of a sudden the JVC car stereo says "reading" and then "can't play" every time I try to plug in my iphone through the USB jack. What could have happened while we were gone for the day to make the stereo stop being able to read my phone? Is there anything I can do to get them to communicate again? I didn't change or update anything on my phone while we were out!

If your iphone is working fine with headphones and only has a problem with the car, then I'd guess that it is a physical problem. My first guess is you have some gunk in the plug that is blocking the connection. My second guess is that you worked the port on your car stereo loose from the wire.

I think it is the first guess--I'm not sure the second situation would give you anything at all--it just wouldn't work.

I think it can't read a particular song that is recorded on your iPhone in a different format. Try playing music that you remember it played ok. If this is the problem, you will need to convert all the different formats into the format your car stereo reads ok.

This is the exact same thing that happened to me. I also have a jvc headunit. I was playing my itouch 4g in my car with the usb port, went to walmart, came back out to my car, and nothing. It kept blinking "reading" and "can't play". What happened to me was my white ipod cable that connects to my ipod to the usb port in my headunit had gone bad only in my car. I plug my ipod into my laptop at home, it works great. I tried it once more in my car and nothing. I bought a new cable, plugged it into my car, and boom.problem solved. I asked my car audio guy, and he said many times, the cables go out when using your usb port. So try and get a new cable.