I'm having what sounds like the same (or very similar) issue with my aftermarket Kenwood KDC-MP745U stereo. iPhone 4S, iOS7.
- iPhone pairs with the stereo, phonebook downloads, stereo unit can display music info
- I can initiate/terminate phone calls from the stereo head unit, and I can answer
- Music/sounds/calls play through the stereo
- Controlling music via the iPhone (play/pause, next, back, etc)
The above items rule out a connectivity issue.
- Controlling music via the stereo unit (play/pause, next, back, etc) This worked prior to updating to iOS7.
The stereo unit doesn't appear to have a BT firmware update available from the web site, and the only thing that changed in this situation is upgrading to iOS7.
I have read in other discussions here that restoring the iPhone will do the trick, so will be trying this tonight.
Thank you so much MadMikePDX, I was having kittens as my bt was not working in my madza. It would not come on by it self, I had to go to my phone and select a song and then it would not change songs at all. I rang the dealership, they told me I had to come and see them (I live an hour and a half away) so I googled, read your post and powered my phone on and off, and hey presto by bt is working again. Thank you again.