Ok, Cd changer jamming is somewhat comon on these radios. Usually a switching arm inside the radio bends or breaks and this causes the issue, it can also jam in the mode that detects a cd as being loaded so it can disable certain raio features.
Problem here is that there are no parts offered for this radio other then exchanging your current radio for a core charge on a remanufactured unit from the dealership. A radio swap is uaually around $500-600 though (OUCH!). Some small electronics repair shops are capable of opening and repairing these radios sometimes but again for the cost of that and the fact that these shops are few and far between this poses more issues. Untimately if you need a cd player then you will need to consider replacing it with the dealers parts department or you will need to install an aftermarket radio. Sorry to be the bearer of bad news.