I have a similar, but not identical, problem with my changer--I get an "error" message. I was told by the dealer to remove the fuse for the radio/head unit (under the back seat on my car), wait 15 minutes, then reinstall the fuse and re-enter the program code for the radio. This didn't cure my problem ("error" changes to "no magazine"), but you might try it.
Crutchfield has changers for about $300, and they are also sold on eBay. Be careful to get the correct changer, as some use (I believe) an optical connection. I don't want to buy a new changer until I figure out some way to prove my problem is with the changer rather than the car wiring or head unit.