It is the reason I had mine in to dealer.

The AGW as a genuine MB rebuilt part from the dealer for $200. It will have to have all
correct Features coded to it via SDS, but that is only 1 hour labor. If you are willing to
change the part you can fix for a relatively small price. Until the rebuilt ones were available
the AGW cost over $900 for the part alone.

 

Thanks for your input.
It's against my religion to spend even one penny at the dealer for diagnostics. Soon I may be getting a hold of (some really good) diagnostic tools :tool: and maybe I can figure out the problem.
If the system needs to be replaced, I may just have to live with my the relay "hack". I currently have no battery drain from AGW; the relay turns off AGW when you turn the ignition off.

 

my battery keeps dying too along with my SBC noise playing thru the subwoofer

 

Hi,

I also have a similar problem with my E320 (53) CDI.

My audio system is causing a battery drain. The only way to prevent it from draining is by removing the fuse (by the fuse box near driver side door). Is there a permanent fix for this problem? The battery is fine (had it checked by AA).

Also, my interior lights (all of them) just stopped working suddenly. Any ideas of what's gone wrong or how i can fix this also?

 

The relay solution that I mentioned above worked for me and I didn't bother to change any parts. Have you replaced any of the audio components recently though? The command system? I think one reason that there is a drain from the sound system is because the fiber optical cable is disconnected somewhere. Or if the command has been replaced it may need to be configured properly to your car settings.

Maybe you can do a relay hack and save yourself headache and $$$.

 

if you have a 03 MY vehicle it is likely that your CGW is ruined beyond repair. these days that modue is pretty cheap, maybe 100-250 installed.. but if you have no idea whats wrong with you vehicle the 125 dollar diagnostic is not a bad idea if you have a good dealer nearby..the cost on these vehicles of shotgunning even one part far outways the cost of a proper diagnosis. you drive a benz dont be cheap...

 

I think the suggestion abobe that the TeleAid was keeping up the AGW system is correct. The SRS light was on because the TeleAid was improperly configured. Got that fixed and the SRS light went away.

The cheap fix of using a relay solved my problem. I never bothered on removing relay to check if the reconfiguration of the TeleAid fixed the drain. There are more than one way to fix things. For the dealer there is only one. Their goal is REPLACE not FIX.

 

If an AGW needs replacing MB has them rebuilt for under $300 and about 1.5 hours to replace and version code it.
Three years ago that would have been $1500 and now is under $500 with a one year warranty.
My failed AGW killed a battery. (the battery was still under warranty). It took two trips to get it right.
The first time the version coding was wrong. The second time they had a 20 year MB tech veteran
do it correctly.
Since then all audio related things work much better. BT phone, Sirius, Nav voice and OTA radio.

 

I know it's an older thread, but I wanted to update with my new-to-me '06 E350. I was having the battery drain in less than 2 days with a brand new battery. Amp meter was showing a steady 2.2 amp with random jumps up to 5 when everything was "off". I also had the TeleAid error.

First, the amps dropped immediately when I pulled the 40 amp fuse for the Audio Gateway Module.

Next, I cleaned the antenna splitter for the TeleAid (had the water corrosion that others have posted about). That fixed that error; however, that did not fix the AGW failing to sleep. All systems work, even the satellite radio, and I don't want to spend $ getting a used module and having it programmed.

I created a workaround similar to Hilarushi's, but slightly different (power to AGW cuts when ignition is off). Everything is back to the way it should be...

 

I created a workaround similar to Hilarushi's, but slightly different (power to AGW cuts when ignition is off). Everything is back to the way it should be...

How did you do that? I am not very knowledgeable in these things but I would appreciate some info!
Thanks!

 

I opted to not use a relay after I checked the wire gauges, amp draw, and wire lengths. I tied directly into the trunk accessory outlet fuse circuit for power with an in-line fuse and changed the 15 amp fuse for that circuit to a 30 amp.

Have not had any issues and everything tests and works fine. When the key is turned off, power to the AGW module is cut.

 

Subby541, Please tell me how you did this. I have the same issue and haven't been able to find a solution. Don't want to take it to the dealer as I know it's going to be an expensive fix. BTW, did you have a SRS warning after taking the AGW fuse out?

 

I was surprised at how little the repair was for dealer pricing.

The drain is caused by a faulty AGW. I had mine replaced. Labor was 1.5 hours.

MB dealers sell the AGW as a reman for $231. It is about $170 at parts.com. A new one is almost $900. Reman part # is 211870688988 and they are stocked at the MB warehouses.

Total job at a dealer was about $400. I had the dealer do it so that it had the full one year parts and labor warranty.
I know nobody likes to spend $400, but it is worth it IMO. These AGWs can just get worse. Once mine was replaced the BT phone, radio, Sirius radio and CDs all sounded better.

 

You have to access inside the driver's side trunk panel where to fuses and SAM are. I re-routed the AGW power wire that plugged into the fuse panel. I cut (but left room to re-attach correctly in case the AGW finally needs replacing) the power wire and grafted an inline fuse onto the end. The other end of the inline fuse was grafted to the trunk cigarette power line (on/off with the key). Make sure you are able to access the fuse when the trunk liner is put back together (from the flip down fuse access area).

If/when the AGW fails completely or becomes an issue with functionality, I will replace it and put the power back to the correct circuit. In the mean time, it just wasn't worth shelling out even only $400 when I spent less than $2 in parts to resolve the immediate issue.

 

Thank you for your reply Subby541! I'm going to attempt this. The inline fuse you used was the same amps(40) as the original fuse? Which one is the cigarette lighter power line?

 

Thanks for the info Subby541, a picture of the modification and/or a schematic would be nice.

 

Thank you very much madaniann !!!

THAT is a nice post, really helpful.

 

So, at the moment I have a fix, please don't laugh because it works even though its not how MB designed it. I have a relay that is connected to the fuse for the cigarette lighter, that turns on fuse 6. Anyway this might not be clear but it works.

Run power to the audio gateway fuse via the cigarette lighter? Genius. I have sporadic episodes of battery draining, every two or three months. Dealer has check the codes. Nothing useful. I think I may have something something intermittent in the audio gateway. I'm going to try this fix for a few months and see if the mysterious battery draining abates.

 

You can use the cigarette power to directly power the audio gateway but you are overloading the cigarette circuit if you do it that way.

Using the cigarette circuit to simply power a relay, which in turns powers up existing audio gateway circuit is a safer method.

I will try to do a simple sketch on how to hook up a relay. Relays are just a few box, and that way you will have a perfect solution to your problem.

 

Here is a simple diagram.

I think it is easy enough for most people to do on their own.

Don't try this if you don't know what an electron is.

 

I get it. Thanks. Your solution has another benefit: Not having bluetooth connections linger when parking the car at home. (BTW my bluetooth connections were off when battery drains occurred). This is annoying feature of the Mercedes Blue tooth from this era.

 

DO NOT GET NEGATIVE FROM A BOLT OR CHASSIS.

These circuits are very complicated and you can actually damage them by using the ground where you shouldn't.

Next make sure you find a fuse circuit that is working properly. And I would try to find something not too critical like a cigarette lighter or similar.


See if you can use the power seats fuse, the rear heater, seat heating or rear window roller.

Once you get the relay to click make sure that the fuse you remove it connected in series as shown on my diagram a few post earlier. This will help in protecting the circuit as it was designed.

 

That's the thing, no fuse worked for me besides the roof unit. and that one doesn't seem to turn off when the key is removed. Currently i am following your exact same circuit with the built in fuse, the only difference is i am connected from relay to bolt, rather then relay to cigarette fuse. Your saying I should avoid this? I was inspecting the back of my same to see why i don't have negative, and in the back where it says 12, I'm assuming it corresponds to fuse 12, there is no input wire, is it like that on yours? Anyways thanks for the quick respond.

 

2004 W211 E500

Same problem and has been to the dealership twice. Almost every time it comes back with the problem "fixed." Changed the alternator and both batteries and it has a brand new command unit as well. Nothing world but this last time the dealership asked me how I usually lock the car and I said sometimes i don't or sometimes I use the keyless entry button n the door handle to lock it. And he said just try locking with the car remote and see if that helps.. Sure enough I've used the remote key to lock every time and I haven't had any issues. So try being super cognasent of how you lock the car because I think when you lock with just the remote key it auto kills all things that were still running on battery...

 

My AGW was replaced as it would not shut down no matter what I did.

Had the dealer use an genuine MB OE reman part. The first one lasted a month and the second one is still working fine after 2 years.

 

Hello i have the same problem but when i use my mb star it says D135 short circuit to ground that i must replace the cable. what cable do i have to replace?

 

This is an update type modification to a problem corrected by Subby541 back in 2013. The fix was genius and is proof that sometimes simple is better. In my case the audio system functioned fine but the AGW would not go to sleep. So it drained the battery overnight. I started by pulling the fuse ( No. 6 in trunk a 40 amp fuse). Bingo lucky right off the bat. Had no radio but had no drain either. What I did was isolate the non power side of the 40 amp fuse. On my 2006 CLS 55 AMG the the non power side is on the right side of the fuse as you look at the fuse box from the passenger side. PLEASE VERIFY THE NON POWER SIDE. Use a test light connected to the battery ground terminal and touch the left and then right side of the fuse looking for the side that does not light up,when you touch it with the probe. I then used a blown fuse, soldered wire to the non power side and plugged it into the audio gateway fuse (40 amp no. 6) in the back. Then took a wire and spliced it to the power side of the trunk socket, and connected it to the non power side of the audio fuse number 6 already inserted. Then removed the 15 amp fuse that was for the rear socket (no. 12 trunk) and put a 40 amp fuse in because it was now powering the audio gateway. When the key is on the power goes to the unit and when the power is off there is no power to the unit and there is no need to sleep because there is no power. Ends the problem of an awake AGW. When my unit finally dies and a new one is put in there is no modification to the fuse box just unplug the fuse with the wire on it, remove the 40 amp fuse from the trunk socket No. 12 put the original 15 amp back in and put the 40 amp back in socket 6 and and its done. A great fix by Subby541 and proof that sometimes simple is better.
Sent from my iPad

 

That was great

But you could of taken some pictures at the time, and that would be great to see how to DIY, some times a pictures is better than 1000 words

 

That is one way to fix it.

A genuine MB reman AGW is around $250 now.(new ones were close to $800) It also has the same as a new part warranty.
The only downside to replacing it is that an MB Star computer needs to be used to program whatever audio features your car has into the replacement AGW.

 

It's a cheap and easy way to resolve a complicated thing, good job, but a picture and a schematic for the ones having understanding difficulties in electric/electronics explanations would be far simpler for them.

 

:thumbsup::thumbsup::thumbsup:

 

Bringing an old thread back to life - have a 2005 e500 with an aftermarket CarPlay and rear camera system in place of the command center. Been running a Chinese audio MOST gateway for about 2 years without issues and now my battery suddenly dies and fuse 6 - audio gateway - is suspect. No audio as well. I don’t use the cd player or nav system anymore but I didn’t code them out. Planning on buying a used audio gateway and I’ll recode it and see what happens. Thoughts?

 

I had to replace the AGW and purchased a manufactured one
from MB. Once I had it swapped the audio functions worked
and the battery drain stopped.

 

The audio gateway wouldn’t sleep and was drawing about 3.5 amps on rear fuse 6. I almost replaced it but I did notice on the scan of the MOST fiber ring that the audio gateway was visible but nothing else was (command, cd, navigation). I went around and i optically jumpered out the CD with no effect and then the navigation system. That brought the MOST ring back up and the battery draw problem disappeared on fuse 6. I coded out the navigation and CD system that are no longer used but I don’t think that matters. I have a Creader Elite for Benz by Launch Tech and it’s an affordable, amazing scan tool. It’ll do just about anything on a Benz.