I added a COMAND APS NTG1 and a nav drive from the UK to my car, and was using an OEM 2005.3 US disc for a few weeks. Somehow the disc developed a cloudy spot on it, and would sometimes not be readable until the car was turned off/on.

Now the COMAND or nav drive have somehow gotten stuck with the idea that there is no nav disc. It doesnt even try to read when I load in a disc. I tried the software reset function in COMAND, and I also pulled the fuses for both the drive and the COMAND. Nothing has helped.

Is there a diagnostic error code menu in COMAND where I could clear this somehow so that it would try to read a nav disc again?

TIA, Mike.