iPod Problems with iPod in car?

I have what I think to be an Apple iPod nano 5th Generation. I have it connected to a Cadillac SRX with a Bose system. It has functioned well over the past year and before that worked well in an Infiniti FX35. The problem is when connected to the car system the song shows on the car screen but either doesn't play or shows the song as playing but I get no audio. I have ruled out cables and the Bose system as both work well with another IPOD. The IPOD in question works well with good audio it just won't work in the car. I suspect I've touched a button or have something not set properly. An Assistance or ideas will be appreciated.
Bill

Google produced the answer. IPOD was ejected from car improperly and all that was required is to be reset. Works great now.
Bill