Guys I've done a thread search and I have seen a few people mention my problem in passing, but I havn't been able to find anything on what to do about it.
When I start up my car the radio turns on (MB symbol) and audio starts, then after about 1-10 seconds it will turn off. During this time none of the controls work.
Some times it doesn't do this, sometimes it does it for 10 minutes, but then eventually it will function correctly.
Its not a big deal but its a pain in the butt!! I'm hoping that this is a well known issue with a simple fix, but as I've never seen a car stereo do this I don't know where to start problem solving.

Also, I'm marginally knowledgeable about care stereo hardware integration, and if I have to just replace the entire sound system well then so be it. But if I can avoid that, even better because when its working I'm happy with its performance.

Even if I wish I could connect my cell phone via Bluetooth other than through an FM transmitter plugged into the cigarette lighter. Not very classy.

 

Unfortunately the ‘05 and ‘06 COMAND units are built by Siemens Germany, different from the rest. So even the Mobridge BT units are incompatible. Ask me how I know. I went the Mobridge route in my ‘06. And when it works it’s great. Problem is, when the car goes off, the unit doesn’t go to sleep, so to protect the battery from draining the COMAND system kicks the Mobridge off the optical loop. After a few, several, few dozen, whatever restarts the COMAND system might pick it up again. But for my use that might be months. I ran this issue all the way to the Mobridge CEO, which is how I found out about the incompatibility. “No one is gonna build software compatible for a 15 year old car” is what I was told, even though at the time I didn’t understand what he was saying. The Mobridge is fine did ‘03 and ‘04, maybe ‘05 in some models but not ‘06.

That’s your very long BT answer.

As for the “System Unavailable” message you’re seeing, that’s just the head unit dying. Becker Autosound in NJ can rebuilt that, probably has rebuilt units on the shelf. Same goes for the Bose amp and the Audio Gateway (AGW). Again, ask me how I know.

But given the BT issues, I don’t see myself replacing all these units and have just resolved to replace the whole thing — head unit, amps, speakers, everything. I’ve already done the speakers. Head unit, amp and sub are up next, maybe this spring. Other car projects have been more pressing lately.

GL,

maw

 

Is it possible to just replace the head unit and run new wires to the speakers?
basically bypass the amp/changer with new speaker wires

 

Before you go replacing head units (annoying to do), it could just be your audio gateway, which is in the trunk. If you have any water leakage into the trunk (can come through any of the 3 taillights, is very common on w215 cars, which I assume have similar taillight seals that fail), the water runs down into a dip on the driver's side of the trunk, getting the audio gateway wet and giving that exact symptom. Pull your trunk panels and looks for evidence of water on the left side in the hole. I had the same issue, and replaced the audio gateway, fixing the system for like $50 (part number 2208702989 for my CL65 AMG). You can also install a bluetooth adapter that replaces the CD changer, they're like $185... enables bluetooth calling as well if you run the mic cable (ebay part number 296544793819).