I have a 2009 g37 and while my car was running, I got a no key messages and my nav screen turned off and all dash lights turned off with the car running and could not turn the car off. I was able to get the car to finally turn off and could not start the car also the I could not lock or unlock the car from the fob, I replaced the battery in the fob and still nothing, anyone see this before or know what would cause this?

 

I found myself into a similar problem while experimenting with the AV unit on my sedan:
https://www.myg37.com/forums/audio-v...ml#post4078355

So it there might be a problem with your car AV unit too...