I see your iPod not working and raise you an iPod hanging and even the entire system hanging. This is on my 2011 Equinox, pioneer no nav. Let me describe the 3 issues I've seen in order of severity:
1. Playing XM, connect iPhone to USB, no problem until I unlock the phone to find an address, which causes the stereo to switch to the iPod. Happens every time. Minor annoyance.
2. Get a phone call while using the iPhone or right after plugging it in. Phone hangs for about 3 seconds, won't answer the call, won't ring anymore. Then it answers but it's not using the handsfree. Put the phone to my ear and answer, then 5 seconds later it switches to the handsfree. Has happened twice. Major annoyance.
3. Plug the phone in, start listening to the iPod, then try to make a phone call. Just one ring, then silence. Hung up, tried again. One ring, then silence but the entire system is hung. Stereo won't switch sources, won't turn off, no voice commands, no onstar, nothing. Unplugged the phone, pressed the off button for seconds, nothing. Had to pull over and turn off the car, open the driver door then restart (windows anyone?). Fortunately only happened once. I wonder is crash detection would still work while in that state. Showstopper.
Anyway, I still love the car, I'm mentioning this to the service guy tomorrow to see I there are any TSBs or anything else.