I've been seeing this issue from time to time. It happens with all CDs and with no apparent root cause. At least 4-6x an hour this will happen.

I'll be driving along listening to a regular CD and then boom, it's changed to the FM radio.

And the wierdest part the radio station is not even in my presets. It always changes to the same station 97.9.

Anyone ever heard or seen this before? I don't want to start the dealer process without at least having an idea if this has been seen before and what the fix was.

 

Not quite the same, but mine has problems with skipping. Several times it has started skipping, stopped playing then switched to FM (don't recall which station). I suspect the problem may be dirt buildup around the laser. I am going to try taking the cover off and clean it with keyboard cleaner (compressed air and halon). If it works I'll post it as a new entry. Good luck!

 

It's an issue inside the radio with wiring, dust, or something like that which is causing the functions to cross each other or short out. Either purchase a used volvo radio from a junkyard or online, or go to Best Buy or something like that and pick out an aftermarket deck and have them install it.