I recently had my 2002 CLK55 AMG in for service at my Indy mechanic. Its a long story but the short of it is this: I had to replace the battery and he cleared all of the codes that were in the system. Now my radio displays this message. I spoke with the shop today and they said that they would have to have me bring the car in to correct this. I asked if I could just disconnect the battery and reset the radio with the anti theft code. They said do not disconnect the battery at all cost. I've unplugged the cd player multiple times with no luck. Thoughts?

After disconnecting the battery, a stock car requires reloading the security code in the radio, a re-sync of the express windows, resetting the memory in your seats, resetting the sunroof, and clearing the ESP error by turning the steering wheel from lock to lock.

When you unplugged the CD changer (which I took to mean the power cable), did you also reseat the fiber cable? Clean the threads/ground? Check the fuses to ensure the changer gets power?

Back when I used my changer (a long time ago) tapping the changer cleared the same error.

Yes, I did reseat the fiber optic cable. The changer is getting power as I have ejected the cd cassette multiple times. Oddly enough, when I pulled the fuse for the radio I was shocked to find that the radio still worked. Odd isn't it.