Error message says cd is not a map disc when nothing has changed since it was working. Everyday same scenario. Works for a couple of hours then quits reading the cd

Both. Check the power line that is supposed to power the clock and memory circuits when you turn off the ignition.

And your player has lost the ability of the laser to focus on the disc - hence the error message.

so is this a stock RAD/cd?
stock JBL 6 disk player in dash>? or? what? name and model #
mp3 and wma format. but not DVD
or
JBL premium 4-disc in-dash CD changer
io the single disc player, 3 kinds sold. new.

and now comes the big question.
TELLS where you got the disk, or name it, or tell how it was made if home made. we dont know that.

is said CD a CDDA? or not. (always try CDDA first)
is CD a real music disc. from a real store, CDDA, is that.
or CDR, or DVDr, or CDRW, or other record-able media
is music MP3? files.
see, the old units dont play modern media.

try 2 real discs, not scratched.
do they play?
one other way, is to name the radio, brand, like JBL then get the
p/n off it. (hard) then look up the product data sheet on it,
bingo, what it can and can not do is there.

but this does it all, mostly
does what yours will not do.
http://www.flyaudio.net/product_id.asp?id=113

This is a common navigation radio issue on this vehicle. The message "Map DVD read error" comes on randomly.... sometimes it works, sometimes it doesn't. Make sure your Map DVD is clean and without fingerprints or scratches first. If it the disc is okay, the issue, unfortunately, is within the radio itself. The only correction I've seen for this problem is to replace the radio itself. Also note, that if the radio is replaced, it will have to be reprogrammed by a GM dealer to correctly set up your vehicle's options and learn the vehicle's VIN so the radio will unlock.

Do you have a solid state drive on the Nav system or do you have a hard drive that you actually load the maps from a cd into? If you load your maps from an actual cd then then I'd be checking that drive. The armature may have failed.

A couple of different possibilities here but this is a typical problem when it comes to the MB cd changers. Before ruling the cd changer bad, check the spring settings on the sides of the changer. Make sure they are in the 'H' position since it sits in the glovebox. The Mercedes cd changers don't have a reset button. 95% of the time its the cd changer that is bad when this scenario happens. Its caused by a linkage that gets knocked out of place internally of the cd changer. Also try not to use burned or homemade cd's as they can also cause the cd changer not to read the discs anymore.If your cd changer is brand new or a factory rebuild then the dealer should change it out no problem since MB cd changers are known for this problem. Also the version coding needs to done to configure the D2B fiber optic ring properly.

If the cd player doesn't load discs and play them and gives one an error message, it could be that the mechanism is worn out and is in need of replacement, either by taking it to a specialist who can change it out, or by replacing the whole radio/cd player with one that works. The latter is the more common method.

Hi i have the same issue same 2004 model year. Its reads...
"Unable to read data, Check if map DVD is Correct"....what? I cant play a dvd but it plays all my cds so far. Can someone please help me with this problem!!! Any Solutions?

The CD laser is dirty. Use a CD cleaner disc first, before replacing
the head unit. Good luck.

My endeavor has done this error 3 a couple of times and the cd changer basically shuts off all lights and won't do anything. Someone on another solution page said to slide a credit card back and forth in the cd opening to fix the problem. I've done this both times and it has made the changer play again as if nothing had happened : )

Well if the unit came with car over 10 years old, u can't clean it might have to just replace. buying a new one will cost as much as trying to fix that one.