E55 Radio Issue Is It The Audio Gateway? Or? No Battery Drain?
11-04-2018, 01:44 AM
#1
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
E55 Radio Issue Is It The Audio Gateway? Or? No Battery Drain?
I have the normal issue where the stock radio in my E55 will start up, flash the Mercedes logo and then shut off. I have the fiber optic loop for testing the different components. I have tested the navigation player in the trunk, there does not seem to be a voice recognition module (looks like there never was one) but the wiring is there and I tested the cd changer plug under the ashtray. It does have a CP (communication platform) that is located next to where the voice recognition module would be but it does not look like a standard fiber optic plug? I am now down to the AGW (audio gateway). Usually if the audio gateway is bad then the battery would drain and this car is not doing that. Is there anything else that could be causing this issue? I don’t want to buy another audio gateway if it is not the problem. Thanks
11-04-2018, 03:47 PM
#2
Super Member
Join Date: Sep 2009
Location: Orlando FL
Posts: 935
Received 74 Likes
on
58 Posts
a unicorn tuned p30 e63
your problem is probably the AGW. i had a similar issue with my E55 back in the day and i replaced the BCM and got no luck (cheap to replace) i then ended up replaceing the AGW and it was fine. mine would actually turn off and turn back on like urs, i’d get out the car go to the battery , un plug it and put it back in and i’d be cruising. hope this helps.
11-04-2018, 08:15 PM
#3
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
Thanks for the reply. Mine does not work at all (even if I unplug the battery). The radio turns on, Mercedes logo comes up and then it turns off. I know for a fact that the fiber optics do work. Has anybody figured out why this happens? Has anybody tried fixing it themselves?
11-04-2018, 08:38 PM
#4
Member
Try disconnecting the battery (or, preferably, just pulling the fuse for the audio gateway) overnight and then reconnect in the morning. If you have an audio gateway problem, this will often fix it temporarily (probably only for a few hours). You will need to disconnect it for several hours to have any affect because the power supply inside the AGW has large capacitors which will keep it powered for a while.
The audio gateway does not (always) cause battery drain when it fails. As far as I know, those are two completely different problems (ie. when it causes battery drain, it usually still works).
The behavior you describe sounds like the MOST system is not operating (correctly), and this is usually caused by the AGW failing: the AGW is the MOST master so without that, there is no MOST function (although any control unit can completely disrupt MOST). You say that you checked it... how?
If you have a capable diagnostics system, check for communication with the audio gateway. The gateway communicates directly via CAN and all other comand related control units must communicate through the audio gateway (via MOST) to reach CAN. If you cannot communicate with any control unit (including the gateway), that is most likely causing the problem. If you can communicate with it, the AGW is probably fine; check for fault codes and check actual values for MOST ring status. Before replacing the AGW, check for proper power, ground, and CAN voltages (usually approximately 2.4V and 2.6V, although sometimes the older cars like this can be a bit different). If you have power, ground, and CAN at the AGW and no communication, it has failed.
If you do need an audio gateway, you can get a re-manufactured one from the dealer for a very reasonable price (as far as MB electronics are concerned). Make sure it's re-manufactured: new is well over $1000 and has very little, if any, advantage.
The audio gateway does not (always) cause battery drain when it fails. As far as I know, those are two completely different problems (ie. when it causes battery drain, it usually still works).
The behavior you describe sounds like the MOST system is not operating (correctly), and this is usually caused by the AGW failing: the AGW is the MOST master so without that, there is no MOST function (although any control unit can completely disrupt MOST). You say that you checked it... how?
If you have a capable diagnostics system, check for communication with the audio gateway. The gateway communicates directly via CAN and all other comand related control units must communicate through the audio gateway (via MOST) to reach CAN. If you cannot communicate with any control unit (including the gateway), that is most likely causing the problem. If you can communicate with it, the AGW is probably fine; check for fault codes and check actual values for MOST ring status. Before replacing the AGW, check for proper power, ground, and CAN voltages (usually approximately 2.4V and 2.6V, although sometimes the older cars like this can be a bit different). If you have power, ground, and CAN at the AGW and no communication, it has failed.
If you do need an audio gateway, you can get a re-manufactured one from the dealer for a very reasonable price (as far as MB electronics are concerned). Make sure it's re-manufactured: new is well over $1000 and has very little, if any, advantage.
11-04-2018, 09:02 PM
#5
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
Thank you for the detailed response. I took the actual gateway out of the car and let it sit for 4 hours. I put it back in and still the same thing. I have no way of testing the can bus. All that I have is an obd2 computer that should pull codes. When I put a fiber optic loop on the navigation dvd player connection and shine a light into the AGW fiber optic connection a red light comes on. I then turned on the head unit and the Mercedes logo will stay on consistently until I take the light away and then it turns off. Hopefully that made sense.
11-04-2018, 09:18 PM
#6
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
Come to think of it, it is starting to sound more and more like the AGW. What tells the AGW to turn on? I am guessing the power from the radio or remote wire. The AGW is getting 12v.
11-04-2018, 09:22 PM
#7
Member
When I put a fiber optic loop on the navigation dvd player connection and shine a light into the AGW fiber optic connection a red light comes on. I then turned on the head unit and the Mercedes logo will stay on consistently until I take the light away and then it turns off. Hopefully that made sense.
Further diagnostics to confirm that the AGW is bad is very difficult (impossible, really) without a high level scan tool. Try this: disconnect the MOST connector on the AGW then disconnect and reconnect power from the AGW (it's a 4-pin connector including the 2 largeest wires). Once power is re-connected (the key doesn't need to be on), you should see "random" flashes of red light from one of the MOST ports for several seconds. If not, the AGW is almost certainly bad (but if you do, that doesn't necessarily mean that it's good). Normally I recommend proper and complete diagnostics before replacing parts, but if you don't see any light from the AGW, I would recommend replacing it because "proper diagnostics" at a dealer or specialist will likely cost nearly as much or even more than the reman control unit (and if you don't need it, you could probably recuperate a good part of the cost by selling it on ebay).
That's a good question and I'm not exactly sure. All MOST control units are "told" to turn on by a 12V "wake up" signal, but I'm not sure if it's generated by the AGW or by the headunit. Regardless, the AGW should know to "wake up" by CAN (it should be awake and communicating whenever the car is turned on, even if everything else on MOST is off). My best guess is that the AGW wakes by CAN and then tells all other CUs to wake, but I may be wrong about that.
Last edited by sjc246; 11-04-2018 at 09:29 PM.
Trending Topics
11-04-2018, 09:41 PM
#8
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
Well, I unplugged the power to the AGW and unplugged what I think is the MOST port (where the fiber optic line goes in)? Plugged the power back in and there was no light flashes at all. Now, I am assuming that means the AGW is bad? If I get another used AGW that works and is the same model number, will it need to be recoded? The model number is the same but the 211 part number is different.
11-04-2018, 11:41 PM
#9
Member
11-05-2018, 12:07 AM
#10
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
Good News! I just put the new AGW in and it works! It did not work immediately, I had to pull the 40amp AGW fuse in the trunk and reinsert it. After that, it turned on and works like a charm! Thank you everybody for your help!
11-06-2018, 10:33 PM
#12
Senior Member
Thread Starter
Join Date: Nov 2014
Location: So.Cal.
Posts: 299
Likes: 0
Received 0 Likes
on
0 Posts
2003 W211 E500
