I have a question. My radio stopped working a few days ago. No sound from CD changer, no stations showing on screen, no voice command on steering wheel, or navigation but the navigation maps is working fine.. just no sound. I was told that the CD changer (w221) is bad and needs to be replaced because it's the controller of everything. Wouldn't my Nav not work if this is the case? Also, the changer is lit up and when I push any button on the changer, I can hear it going thru the commands as if it's trying to play, so I'm questioning if this the the problem. I'd like to know before I spend $1500 to replace something that isn't the problem. Thanks

In the 221 the amp (located in the trunk) is the audio gateway (controller) and that's probably the source of the problem, but the failure of any component in the loop can shut down audio as well. Best bet is to get it to a shop with an MB diagnostic terminal and see what fault codes the gateway has thrown.

I took it in for a diagnostic and was told it "could be" the CD changer because it's the brain and not communicating with the amp, but he shows the amp is working. confused.. I'm just afraid to pay $1500 to replace a part that isn't the problem. Thanks for replying

Did they print out or tell you the fault codes? There's a member who's great at this stuff but he'd need the actual codes.

Often a software update will fix these kinds of problems. It isn't very common for electronics with non-moving parts on these or any modern cars to just fail. As Mike mentioned, find out the codes that came up on DAS and Konisteger (sp?) can probably lead you in the right direction regarding needed repairs and service bulletins. He seems to be the most knowledgeable member of this board for this kind of stuff. The S-class is the lowest produced car in the Benz lineup, which means that service techs usually have the least experience when it comes to working on them. So issues like this that are not common might not have been researched enough by the service advisor or tech prior to guessing what might actually be causing the problem.

OK the code what was given to me is:
D104 most ring open at position 1 open.. he says the signal is going out but not coming back

So all of the components...terrestrial radio, satellite radio, voice control, DVD changer, amp...are arranged in a continuous loop, where each piece takes in fiber optic signal and passes it along to the next piece.

If one piece is down, any pieces down line from it go dark as well. The components are arranged on the ring by position. Whatever is at Position 1, and I'm guessing it's the DVD changer, is down.

If you don't mind losing the changer, MB sells a fiber optic bypass for $7.00 that closes the loop, but you'd need to confirm the DVD changer is in the #1 spot and that it can be bypassed. If it's part of the COMAND module it can't.

You Are AWESOME! you repeated verbatim what the guy told me, except the part about the bypass. I will ask on Monday about the bypass option but I believe he told me that the DVD changer was the control module "the brain" is what he called it and it is position 1.

Yeah that's what I'm afraid of. The DVD unit might be the one bit that can't be bypassed. I'd hunt one down on EBay I if that was the case.

I found one on Ebay for $690... they seem to be running around $1,000.. thanks for all of your help.. I feel much better getting an outside opinion becus I didn't want to spend that money and find out it was something else .

That sounds like a safe bet. Let us know how it goes. You ruled out all of the COMAND fuses, right? If not, pull the giant fuse chart from the spare tire well and hunt down any that relate to COMAND. I think you said it still loads but won't play, but I'd check those fuses just to be sure.

I asked him if he checked the fuses, he said yes.. that's what troubles me... I can press , for example, the eject button and you can hear it attempting to eject something.. and all 6 slots are lit up red, so it has power of some sort... that's why I questioned if it was really the changer. My fear is, I'll replace it and discover it's something else. This will get pricey QUICK

Now I'm being told that the amp needs to be replaced as well. I found out today that the amp is NOT the original amp that came with the car and when they replaced it, it was never coded so it's possible that the amp caused the changer to stop working so BOTH need to be replaced. Has anyone ever heard of this happening?

MY08 part #s. If vehicle is being diagnosed with MB DAS it should identify malfunctioning part. Before replacing anything check to see if amp part # is listed below if so, request they clear fault codes and code amp as a first attempt repair. If CU and/or amp are, in fact, malfunctioning you now have replacement part # to choose from.

I have straight pipe in place of secondary cats in both videos

Hi. I have an 08 s550 4matic with the same symptoms Then043. No sound, CD's won't play, radio won't show stations, and BT phone connects but obviously no sound or mic. I do have maps, and GPS (it just won't speak). I checked the fiber loop as described above and it seems to be closed (okay). So my question is, are there any tests or symptoms I can check myself to zero in on either the radio/cd changer (in the dash) or the amp (in the rear) is the root cause? May not be related but now my backup camera works intermittently.

If you can get it to a dealer or indie with STAR the system will tell you what's wrong. Sounds like a bad amp but the components are so expensive it's worth a hundred bucks to get it scanned.

Thanks for the quick reply Mike!

hi. Did u fix this? Am having this problem so bad

hello mike my name is Levi i have 07 S550 w221 with most /audio problems is base model so i have only sat radio and tuner(amp) in the trunk. i have xentry/das scan tool with code for most gateway report open loop unknown position d100 i also have a by pass loop tried in all possible modules with no success no sound nav works cd changer loads and reads cds but no radio station numbers are display and obviously no sound, is it possible for the comand to go bad even tho still it appears to be fully functional i could see light on the fiber optics only when i reset the ring with scanner. any help would be much appreciated.

I had a similar problem with my radio everything worked but no sound first turn on the car in on position do a reset hold CD eject button Intel the screen goes blank if that don’t work you need to try a soft reset by taking out all the fuses for 10 minutes In the whole System gps radio CD DVD Gateway amps Voice control module One fuses boxes next the the front door one in Engine compartment The other behind the rear seat I’m not going to go through all the fuses but like I said whole system if that doesn’t work it’s your amp if you live in the USA there is a company called M&B specialist you can find them on eBay or www.mandbspecialist.com I used them and my radio sounds better than it did before loved it and it comes with 6 month warranty for $300 you need to send it out but I’ll tell you highly recommend it

Hello Then043, how are you? please did you ever get this issue resolved? I'm having the same issue. My amp won't even have ignition trigger power..

Hello my name is Alexander I work with this units, what exactly is the problem you have?

Hello you have problem with the amp, most of this amp go bad some transistors but most the commons problem are the PCB controller,is the one that control all the analog and digital signals.