sigh...it didn't work..still the same...start car, music plays then poof its gone after 5 mins. bluetooth/cdc not found. just the whinny ground sound.

 

let me ask you to do something before telling you the amp is bad and its gonna cost $$$$ to fix it??? i think there is an amp under the driver's seat of your car. look under your seat and see if you can see anything with bunch of wires and fiber optic line connected to it. now listen, i think its a very tight fit under there and most people had to remove the seat to actually get to it but??? i dont know how much you really want to do here and even after disconnecting all the connections and reconnecting them, may not even work but its worth trying...... are you up for this knowing that it may not work?? being that you are just absent sound, it maybe just a connection on that amp?? want to give it a try!!!

 

and if you could/don't mind, could you take some pics of the amp?? with all the connections as it lay?? thanks!

 

sorry, after searching around the damn amp is under a panel under your drivers seat. you wont see it just by looking under your seat. sorry about that. thats the reason why the seats were removed so the panel can be lifted to get to the actual amp to disconnect and reconnect the wiring....... man i don't know if you want to go thru with this???? your call.

 

I have a similar issue with my w219 2005 CLS55, the audio will play fine, can be CD, radio any source for that matter, and while driving the audio will cut for a few seconds and then audio comes back.. If I am connected with Bluetooth via phone and bottom right of the radio screen has the signal strength of cellphone network when the audio cuts for those few seconds the Bluetooth connection to phone is lost as well then all returns to normal.. Then intermittently it does it again and again at differing times. My previous car, C32 amg did exactly the same thing.. Wtf can't Mercedes build a proper audio system for these cars. I am thinking the problem is a faulty AGW unit? Any thoughts?

 

you are right C32Owner.... only problem in this case and unlike the cls and the w211 where our units had the agw and amp built in together whereby you could not differentiate which one was "bad", the ml320 have the amp and agw separate. of the 2, the amp is the less costly to "play with" and if the connections removed and reconnect do not do anything, then STAR would be next option and it will surely say the AGW. the agw is costly, running up close to and sometimes over $1000, but mercedes will want to replace that first and then back diagnose from there. i am hoping its just the amp for our fellow member and hoping this small ditch effort provides some relief???? we shall see........ i agree with the setup of our audio system: its terrible and very expensive not if it fails but when if fails!!! take care.

 

Thank you my friend green. I bought the car 2 years ago, the radio was working fine all the time, no issues, tell I used the new duplicate key. The cd changer place is empty, the door is opening but it’s empty, and it was working fine as well until the radio stopped working. I got the car from a dealer, yes, I do remember that he said to me that the car is base. Noting was add or removed from the car, the instrument cluster died suddenly and I replaced it with same part number, also please note that it died when I used the duplicate key. I believe the head unit is , because if I connect the AGW fuse 6 in the trunk, the car starts draining the battery, also when the fuse is connected, I can see the MB logo, and sometimes the initial screen with radio sound before it shuts off. I think the fiber optic cable is damaged as per your conclusion. The only thing I noticed before the radio stopped working, that there was a minor leak in the trunk from the left side, the leak was from the airevent and I sealed it. But this minor leak was causing a humidity in the trunk, and as you know many fuses and cables are in the back, and they don’t like humidity, maybe this damages the cable.

 

tell you what: due to the fact the system did indeed work with the car just like it is and you have already changed out the agw, then it leads to either the head unit or there is a fiber optic line damage/cut. pm me your address and i have a used head unit that i just removed from my car and i know it works, only the volume button acts up sometimes (turning vol up, doesn't go up as fast but when turning vol down, goes down in light speed---used my steering wheel controls for it mostly due to this flaw). hell just pay for shipping and honestly if it works, you just keep it and rock on. this one will be on me. and after installing this head unit, if the system does the same thing with this head unit well then, you now know (barring the fact the both agw could not have been faulty) that you do indeed have a fiber optic line problem. take care!

 

whether your system works with my head unit or not, you can keep the head unit, you wont have to waste any money sending it back. wanted to be clear here. i dont like to "sell" anything if its not working right and although i got this from someone like it is, i dont feel right in selling it with this issue. reason why i have had it in my attic and was planning on using it for parts?? but i know it works!!!

 

so, the sound came on and off again, so i thought, it must be overheating, the amp, and I cranked the AC to the underpart of the dash, and within 3 mins, BAM, sound. So it is the amp and its overheating...I can always just drive with the air pointing down to the feet..BRUTAL. I"ll try this trick tomorrow on my drive to work and report back if it works!

 

i hope it works. in the ml, the amp is under the seat and the agw is under your drivers side dash. so it is the agw thats getting overheated and/or going bad. so i hope this ac trick works for you but if it doesn't, then you now know that the agw is the culprit!! take care and good luck man!

 

Thank you so much Green for the offer, highly appreciated your kind help and prompt respond, thank you so much..... I would like to try the head unit, but unfortunately i am afraid that i can't take off the head unit, i don't know how to do that and have a concern to break something in the dash. Reading your respond to the ML, remembered that the star told me that the AGW start's working for seconds then getting overheated and shut off, that's why he recommends to replace it. does this make sense

 

the AGW will sort of warn you that its going out or getting worse but i thought you mentioned you replaced the AGW already??? of the 2, i would think it would be the AGW thats bad if you have not removed/replaced it. hell i believe i have one of those too.. lol. i got a lot of parts!! but anyway, think it over and let me know how you want to proceed. the head unit removal is very easy but if this will be your 1st time doing it, it can seems like you will either crack or break something doing it..... open the ashtray door and pop up the shifter plate. once popped up, move shifter plate back and lift up on the ashtray, right below the "cd cover" will be some screws on each side of that unit. loosen them up and pull, will be a connector to disconnect and then on each side of the headunit underneath will be some screws to loosen, only loosen them (they do not come out) and your headunit is ready to be pulled and removed. wished you were closer or around, could do this whole remove and replace like under 30 minutes man!! its not bad at all. but its up to you but if you want, the dealership do have or can get refurbished AGW and they are like $400 and will take your unit as a core exchange. this is not a bad route to go and make sure you get them to tell you what type of warranty you have with the refurbished unit. and when/if somethings not right, just take it back for them to fix. all in all, i would expect somewhere in the ballpark of about $980 for everything??? have a great weekend and think if over my friend!!

 

thank you my friend. yes i tried 2 AGW's, the 1st one i replaced didn't make any change, the battery still drains and the Radio died. so i returned it back to ebay as i thought its faulty. then i bought anther one recently and put it on the car, also nothing changed , battery drains, no radio. the part number of the two was matching the original one. when i went to the star, my original AGW was on the car. so i have tried 2 already with no result. that's why i am thinking that the problem is in the fiber optic cable, but what make me crazy, how the cable would go faulty?

 

yeah man, thats a tough one?? seems like the only time the fiber optic line could have gotten damaged was when they replaced the agw (2x)?? but you had this problem maybe from a faulty agw from the beginning??? so you are thinking you are back to the agw needing to be replaced?? send me the part number of the unit you have installed in your car if you have it somewhere on a form/bill of sale etc etc.... i may have a working agw in my attic. (not ask)... want to help but i can see what you are saying...... you have to have a "working" agw to see if the rest of the system is "ok"... hell its only 2 components on your system, radio and agw. its either one or the other!! sort of makes it very easy, but you cannot bypass the agw nor the head unit. wow! this sucks!!!! the battery drain points to the agw not shutting off and staying "awake", some of the agw with the fan, you could hear the fan running while the car was off. it just hard to believe you have had 2 agw and they both were faulty??? what are the odds of that!! man, i hope its not the fiber optic line. that would be terrible!!! let me know what i can do to help man, im here and i will check on that agw let you know what it looks like??? have a great weekend man!!

 

thanks my friend. i am attaching pic of the AGW's part number. the two AGWs i had installed my self, and i was very careful about the fiber optic cable, i dont think that i screwed it up. there is no fan in my AGW since no nav i believe. thats what making me crazy , that i have only the AGW and the Radio and still cant figure out the problem, although with star help ... really i dont know what to do, seriously thinking to sell the car, but who will buy? no radio and no mileage on it zy:. i love the car, but without radio its sucks. i already bought the fiber optic bypass, but as you mentioned, i have nothing to bypass. .. also i noticed that i have to remove fuse 6 from the trunk (AGW) and fuse28 from the interior (Radio) to stop the battery drain, i have to remove both? i tried to remove only 6 in the trunk but the battery still drains, i have to remove number 28 as well, any thought why both should be taking out to stop the drain. Thank you my fried for your time and the valuable advises.

 

when the agw is not functioning properly, the agw never turns off and stays on the whole time killing the battery. sounds weird but it just stays on and the ones with a fan, you can actually hear the fan running while the car is off. my agw to match your unit as close as possible as this part number:
A211827"46"42.....

my unit part number is different at the quotes. your part is "43" and my unit is "46" only means my unit is newer than yours, not by much tho. no fan on my unit either.

look, whenever somethings not right, we all want to get rid of our cars and get something that is newer and no problems but eventually if you keep your car long enough, surely, you will have a problem!!! don't give up just yet, this is a very minor problem and one that i think you can fix and i promise you, You will feel so pumped and glad when you DO fix it!!! these cars are very sensitive and funny with the connectors/airbags/seats etc etc etc....

let me share my experience i had just this past week. did my oil change due to its been over a year and although i only drove the car 3k miles, i dont like the synthetic oil to be in the car for more than 1 year or 10k miles max. so when changing the oil, the front of car had to be placed on jackstands and the oil done. afterwards, going for a test drive the car symbol came on my car with the up arrow and message "VISIT WORKSHOP" as if to say that the airmatic pump is not working or malfunctioning???? of course i was disturbed! all i did was change the oil???? got my STAR and it said something about the right Accelerometer Sensor fault?? knowing what i know about these cars, i just took the connector off, blew some air into it and reconnected it and made sure it was a firm connection, and BAM: no more faults, no arrow, no VISIT WORKSHOP message!!!! damn thing was fixed or better yet, problem solved!! sometimes it is as simple as that. hang in there and at worse, you will have learned something about your car and more you know and do, more comfortable you become with the Mercedes Brand and all its quirks and weird happenings!! let me know what/how you want to proceed. take care.

 

Thank you my friend for your helpt, i highly appreciate your time and support. i am not sure what will do next, i tried every thing that i can, and i dont think that the two AGW's were faulty, at least one of them is functioning, the car has now only 78000 km, the radio stopped working, then the instrument cluster, and now i have teleaid malfunction.. visit workshop. a friend told me that maybe the AGW's that i bought need to be programmed by the dealership. i dont think that they will help. Thank you my friend, i am happy to know you in this forum, you were a great helper. thank you so much. have a great weekend.

 

i know its frustrating. give this a shot. take it to the dealership and just tell them the radio just stopped working. (if you did switch out the original agw, they may want it to program the replacement you have there now??). let them know that you thought it was the agw and you switched that out and the radio is still not working. ask them what is the expected charge to get the diagnosis of what they think is wrong (ie need a new agw, or head unit or etc etc??). i am hoping that for the fee they will charge you for them to find out what is wrong, they will "program" the agw (well in this case, they will eliminate everything on your replaced agw except the head unit since thats all you have in your car, often times- if an agw needs to be "reprogrammed" the dealership goes into the agw via STAR and make sure all necessary components of your entertainment system is on the replaced agw like say you had sirius or cd changer or voice command-- they would go into the agw and make sure these components of the agw are turned on or made available to communicate with the agw). afterwards, the dealership (after say a day or two) will report to you what it will take for your radio to be fixed. depending on the amount they are talking about, you can decide either go with them or keep the report and at least (hoping here) that the agw will be programmed??? here's the thing: if you decide to let them fix it and they do all this work and its still not fixed then you may very well come to the conclusion that you have a fiber optic break somewhere. since they did not fix it, they should not be charging you that crazy amount quoted to "get it fixed"!!! if they think its a bad head unit and want to replace it, let them know you got a head unit and you will bring it up there. pm me and i will send you my head unit. do not let them charge you for a "new" head unit!! that will run your bill into the $3000 to $4000 worth!! ouch!!!! so you may ask: WHAT WILL I ACCOMPLISH BY LETTING THE DEALERSHIP FIX MY RADIO? you will know for sure that it wasn't your agw or your head unit, that indeed, somehow a fiber optic line got damaged!!!! and then you can proceed from there!!! this will, i hope, bring you a peace of mind about it and give you a plan of attack to finally get somewhere with your radio!!! btw: i'm not sure if its "necessary" to get the agw programmed??? some say yes and some say they just replaced and it worked without programming?? its weird for sure! worth a shot??? THINK IF OVER!!

 

hello...damn my AC trick stopped working and now the sound is gone again...do you think it could be a sound module error?

 

if its just the sound and everything else is working, it may very well be just your amp is bad. really isn't a "sound module", its all tied into the amp and if no sound, usually, i say "usually", its the amp that needs to be replaced. have you placed it on STAR to see what diagnostic has to say??

 

Thank you very much my friend, this is a brilliant idea, how did it come to your mind, you are amazing man. I will book an appointment soon at the dealership and tell them exactly what you told.Yes, definitely they will program the AGW thinking that it’s the original one, as if I ask them to program the purchased one for sure they will refuse. I will give this a try and let you know. Thank you soooooooooooooooooo much my friend for the awesome idea.

 

Hello..! so i took the car to merc last night....225$ for a diagnosis...its water getting in to my ML320 2007. so they wanted to keep the car further to remove the carpet.seats to see where the water point was...i said no thanks, i can do that myself. SO i'm thinking water drains, AC....what do you think...anyone have this problem before?

 

This is a great thread with lots of good info! Thanks to all that shared their experiences.

I have a rather simple question, regarding battery drain due to possible issues with the AGW. Background - 2003 E500 with Harmon Kardon 6-CD changer and tape unit. Radio works fine. But I've had battery drain twice in the last few months. SRS light is 'on' (following replacing the main battery in September). The AGW scenario sounds logical, if it's not shutting off (or coming on by itself) and running the battery down eventually.

My question - removing fuses #6 and #28 will cut power to the radio totally, correct? There's no way to bypass the AGW and have the radio function (since it's a fiber loop), right? Having not seen the fuse-box layout, can the fuses be moved on the fuse board to only be key-dependent? I know with the cigarette lighter fuse, you can place it in different slots on the fuse line, to make it have 'constant power' or have it be 'key-dependent'. Is this possible with either/both of these two fuses (6 & 28)?? If it is, that would resolve the battery drain issue.

Thanks again for the info provided here!!!

 

curious about the SRS light?? don't know why this light would remain due to battery removal or battery disconnect?? would look further into the SRS light remaining on... the AGW is a common battery drain but also another main culprit for battery drains are the passenger/drivers seat modules. don't know why these seat modules have this problem but they can also be the reason for battery drains. i have not seen or know if its possible you can make the agw (fuse 6 and 28) from unswitched to switched via fuse swaps etc etc... an idea worth looking into..?? if the agw is remaining on, its malfunctioning and will eventually shut off. maybe better to look for a used/better agw??