MTBSully

Bought my E55 a few weeks ago and have just started messing with it to solve the few little quirks that it has. One being that it needed a new battery when I bought it (which now makes sense). I put in a new battery and the car has been running well, but it seems the battery would die overnight, over and over again even after I repeatedly checked to ensure no lights left on etc. I finally had time to do a parasitic draw test last night. I found that even after the car was asleep, i would see a constant current draw of 3-5 amps, plenty to kill a battery overnight. I also noticed that the DVD navigation unit seemed to be almost constantly doing something. I started pulling fuses in the trunk 1 by 1 until i got to fuse #6 in the trunk, which dropped it down to a much more reasonable 40-60 milliamps almost immediately. Well, theres my problem I suppose.

Fuse #6 appears to be the amplifier/audio gateway, and with a little research, it appears that I am not the only one who has had this issue. I found this thread: https://www.benzworld.org/forums/w21...-doesnt-4.html which highlights which has an interesting fix of powering the AGW with another "key-on" power source which seems like it could work. Another option being to grab a used one off of ebay and hope that it solves the problem. Any other suggestions?

Also unrelated note, before i removed fuse 6 I was trying to get my navigation working. My navigation disc appears to have a bit of permanent "haze" near the center. I inserted the disc but the command unit continued to call for "insert navigation disc in trunk". Im wondering if maybe the nav disc is bad, or if maybe the DVD drive itself is bad. Do they fail very often?

StarvingArtist

It's rare but the DVD players do fail. If it was a bad disc it would tell you.

hachiroku

any module can fail, my central gateway module is doing the same, causing a 2.2 amp draw...AGW can run between 50-400 used. i wouldn't know of this needs to be coded to the car or not. maybe someone else could give info on that?

eurdone

Curious if you got to the bottom of this. Having a very similar problem on my W220. Don't want to roll the dice on a new AGW unless I know it's the problem. I heard a very strange almost alarm sound coming from the nav area in the trunk one night when the car was off.

drothgeb

Hello eurdone, the audio system has a lot of components in the fiber optic loop and if any of the components fail the system will not shut down/go to sleep correctly and cause the battery drain. Best bet is probably to run a test via STAR and see if any faults show up on the audio gateway.

To remove components the fiber optic loop must be disconnected and then jumpered. I'm not sure if it would work but if you wanted another way to test what component was keeping the system awake you could try disconnecting the fiber optic loop and jumping around it one at a time for each component. The fiber optic jumpers can be had for like $4 on amazon.

MTBSully

Yes I did. As suggested in my original post with the link, i simply jumpered the AGW to a "key-on" ignition source. I never had another issue with battery drain for the rest of the life of the car, which was sadly cut short two weeks ago when I was rear ended and the car was totalled:

tlambert

Oh wow that’s horrible. Hope you’re ok. Sorry about your car.

eurdone

Thanks for following up about how you solved the problem. And I'm really, really sorry about your car man. All of our aging Mercedes' are at such risk of being totaled due to lowering values, but they have such high sentimental value. It sucks.

turbonos7

You can buff that out!!! Nah, sorry about your car man. Hope everyone involved is OK!

bloomski

Jus at question. My navigation system on a 2005 W211 CDI wouldn't sleep. My dealer pulled the #6 fuse and the parasitic power drain stopped; but if I put the fuse back in, and then just put a lollipop on the navigation system, would that solve the problem? My question is whether or not the #6 fuse controls both the navigation CD changer and the Aud i ogateway. If the problem is my CD changer for navigation; and I bypass it - will I still be able to get the audio gateway to work?

Diablo_CLS55

did you ever fix out the problem? My radio is stuck on the logo and won’t turn on and is also draining my battery overnight. I believe the fuse or the entire audio gateway itself is the culprit.

bloomski

No I never fixed the problem. There are basically no audio gateways available by the part #, for a replacement. I just listen to the diesel engine instead of the radio. Play music through my phone and portable speaker.

qbmg973

SEEMS LIKE THE CENTRAL GATEWAY CONTROL MODULE IM HAVING SAME ISSUE BEEN KNEW IT WAS THAT BUT MADE SURE FROM 5 different people and shops what happens is water tends to get in the trunk and it ruins the gateway control module which gives communication to every computer in the car literally 💯 u may be a blessing to drive u may not which means it’s bad bad if u can’t drive fix the water leak then fix module unless u want to go over this again