Hi everyone, new here, first post so Hi to you all
I have ML350 2014, 4matic. I installed after market android screen which was working fine. Since this model has fibre optic connection, I had to connect audio cable from Aux connector of Screen into AMI port (using genuine AMI connector) to get sound.
Last week, we had -55 C whole week in Saskatoon and I didn't go out for whole week. Despite car was plugged in (outdoor parking), this Saturday when I tried to start (after 7 days), car didn't have any life at all. Called one friend who tried helping to jump start, after spending almost 1 hour, multiple tries, car refused to start. Next day, tried with a battery booster + jump start, lights would turn on, screen would turn on but engine won't start. I went to Canadian tire and bought a battery charger, left vehicle connected for almost 4 hours, tried again and this time car started without any issue. I noticed blind spot disable, early warning disabled and several other messages started flashing as soon as I drove but after about 30 minutes of driving, all those messages disappear.
Now, everything seems working back to normal, car is starting normal (3 days in a row) but I have no sounds coming to AMI port. If I connect headphone direct to Aux connection on screen, I hear sound so definitely not an issue with screen etc. If I go to command and connect bluetooth, I get sound normal too so no issue with speakers either. It's something happened to AMI connector (in glove box) thats not sending sound to speakers.
* Any suggestion how to troubleshoot this? is there AMI port fuse that I should check? I tried google and couldn't find any useful info. I check with another ami cable so cable seems not an issue either.
* Battery seems working fine now, should I worry about since its 6-7 years old? or it was just a mistake leaving car in extreme cold without recommended ,once a day starting for 20 minutes?
Sorry for long post and thank you or your feedback in advance.

 

Welcome to the forum!

- First off, replace both batteries, main and auxiliary. It's an OE and has tasken care of you since 2014. Give your alternator a break and change them out
- I dunno who told you to start the truck once a day, but that's silly. With a good battery and no parasitic draw higher than .03 to .06 amps, your truck should be able to start after two weeks of sitting there.
If anything, starting the truck every day consumes capacity and 20 minutes at 800 rpm will do little to recharge it. Unless alternator technology has changed, you need to get her up to highway rpm's to
adequately recharge a battery
- Can't help you with the audio, sorry. I also have an aftermarket screen.

 

Maybe do a factory reset on your android unit?

 

Bad things happen when you start a car once a day for 20 minutes:

1. Battery never gets charged to make up for the discharge of starting in that 20 minutes.
2. Moisture starts to build-up in the oil and gasoline builds up in the oil because the engine is not fully warmed up. Engine oil needs to reach 100C in order to burn out the moisture that collects due to condensation! GDI (Gasoline Direct Injection) engines are known to cause fuel build-up in the oil if the engine is not driven enough, Look at the Oil Dilution problem of the Honda CRV Engines.
3. The rest of the drive train (Transmission, differential, axles, drive shaft, brakes) are left to stay frozen get them moving.

 

Thank you peter2772000. Yes, definitely up for both battery replacement. Even thought everything seems working fine now, not looking for another similar event . I am new to this area, in Ontario we never even plug in our cars no matter how cold (It doesn't get above -20 normally with windchill) but here in Saskatoon, it gets to -60 with windchill and I see almost every body plugs in and many sitting there often just for a daily start. What you said absolutely makes sense, a bad practice here I guess.

 

Thank you GLK Super Fan. It is actually not an android issue. Sound is coming out (see attached pic) if I connect a head phone to AUX port of screen. That means, screen is giving output sound as normal but no sound To / from AMI port to speakers. I remember now the guy who was helping me, he made a mistake and connected booster cable's red connection to already connected Jump cable's red. Even it was just for seconds and he removed immediately, maybe that created some type of corrosion and nothing else but AMI port fuse burned out? but I can't find if AMI port even have a fuse or not. Looks like until 2012/2013 models, they did have a separate fuse for AMI but from 2014, it got mixed with audio etc, not sure though.
If I connect command's bluetooth, I get sound normal but as soon as Apple car play kicks in, it disconnects command bluetooth and then I get no sound because it switches to screen/Android.
​​​​​​​

 

Thank you Etienne Lau, yes I am learning these things from here. It is a bad practice here I guess and I was advised by several people as this is how they deal with winter here lol. Most vehicles are parked outside here and every parking spot do have a plug-in to keep block heater connected.

 

FYI, windchill readings only apply to exposed skin. Your car will never be affected by windchill.

 

Hi,

Did you ever fix you issue?
I think I have the same problem, tried using my AUX for the first time this week and I get no sound from it, everything else work fine.
After ready your post, I remember I had a battery drain problem 2 years ago.

 

Unfortunately not, I even replaced both batteries, still have no sound from AUX. I stop using aux and removed it as I am able to connect Phone to bluetooth so music etc plays from original MB audio. I can't play/get any sound from Android screen but I am personally OK with this as I am using android screen for Carplay only.

 

That sucks.

I have 3 options I want to try, no specific order but I'll go for the easiest one first.

1. It's possible this could fix AUX since I have same error with media interface and related to battery drain.
https://mbworld.org/forums/m-class-w...available.html
but apparently the module on a W166 is under the rug under the driver seat, I'm still searching to make sure because it going to be a ***** to get too.

2. Remove a couple of fuses for a few seconds and make sure they are still good. The fuses I'm looking for are in the fuse box F33 beside the main battery under the passenger seat.
If I remove the 4 bolts holding the seat, it should be fairly easy to access the fuse box once I lift the seat forward.
Fuses F30, F47 and Pin 3, 5 in MF2. Hopefully one of them will power down the Communication Telematic Control Module I think it's called.






3. I saw if we unplug main battery for 30min it may fix problems with Command but I can find my radio code anywhere. therefore I'll call dealer tomorrow with my VIN to have the code before trying.

 

Thank you very much, I appreciate your suggestions. Still in travel, will definitely try once back in town. Let me know if any of these helped fixing sound issue on your side.

 

For you issue I would check if AUX is enable in the engineering menu. Specially if when you select AUX you have a message no media interface.
It could be possible in your case, AUX was set back to off, since it's the default because the power was lost.
I notice that you can only have one of the two.

In engineering menu if Media interface is installed in MOST 7.5 UCI - installed (this is Media Interface), your AUX in 7.7 will be off and grayed out.
To have AUX ON in 7.7 you have the go in MOST 7.5 and set UCI to not installed. After that AUX in 7.7 will be available to be set to ON.

Usually most people who needs to enable AUX in 7.7 turn off MOST completely in 7.5 but that also reset all configuration in 7.5 and people complain after having no more sound at all because they don't know to set back Audio source to External Amp and don't have satellite radio because SDARS (this is satellite radio) was reset to not installed.

For engineering menu on the command press 10sec "hang up" + "#" +"1" at the same time go to menu 7 you see menu 7.5 and 7.7
Once finish go back to the first menu on the second page select 9 to reset command. (really don't like the phrasing since it's a reboot)

PS. Don't touch anything else or stuff your not 100% sure in engineering menu or it will cost you a trip to the dealer.