Frank Sansone

Can someone help? When I hit PWR to activate the command sys the screen displays the MB logo but does not seem to load the nav or audio. My 6 CD changer will not operate, audio or nav does not operate. The sys does not turn off when the smart key is removed. Does anyone have an idea about what is wrong. Can the computer be cold booted to fix the problem?

Thanks Frank
fesans@aol.com

Diesel Benz

Usually it is an issue with the MOST fibre ring if the MB logo appears (and possible goes away but the head unit remains dead). Then again it should be more of a CAN bus issue if the head unit does not turn on and off from ignition. You should anyway check the connectors behind the radio and if that does not help, then all the devices in the MOST ring.

tkachster

I had a similar issue with my '04 E320 - the Mercedes logo would appear but COMAND wouldn't turn on. It turned out to be a defective voice command module, which I just had my mechanic bypass in the MOST loop. (It would have been over $1,000 for a new VCM, apparently, but since my TeleAid system was no longer functional anyway - it had never been converted from analog to digital - the VCM could safely be bypassed.) However, theoretically any defective component in the MOST loop can cause the entire COMAND system to malfunction. Have the fiber optic loop checked by a mechanic who is familiar with Mercedes audio systems.

Best of luck,
Tkachster