I just purchased a 2000 ML320 with 66k miles on it. Took it on a road trip this wknd. After about an hour on the road and from switching from a CD to the radio, none of the controls worked. I had to pull over, turn the car off so that the radio would turn off. When I restarted the vehicle, the entire Bose system would not turn on and I heard a whirring sound the rest of the trip. That stopped later that day but now nothing is operational with the system. Any suggestions? Thanks in advance.

Did you try pulling all the fuses for nav / radio and putting them back in?
The radio should prompt you for a code after it has lost power for a while. If you don't have the code, you'll probably have to stop by a dealer to get it. If the radio does not turn on with "CODE" on the screen, you'll probably have to get it checked out at a dealer.

I have no idea if this would help, but like most things with electronics, cold boots do wonders sometimes.

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Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Been there done that. Pulling Fuse #21 and reinserting always works for me. Make sure you have the radio code handy to get things up and running again. My 2 cents.

Thanks everyone! It DID work!! I had John from Benzmobility check it out and that indeed was the issue. Life is good!