I got this message a few weeks ago. I found it was intermittent for a fews days even showing 14v sometimes other times 11-12v. Ended up finally failing.
Replaced the alternator with a new bosch one and all has been well for the past few weeks.

 

Hello I dropped my phone broke my screen phone was getting service the past couple of days sorry about that tomorrow may get a voltage load reader to be positive that both my batteries are performing properly underneath a load and then I'm going to check the load on my alternator while it's running with the device I'm about to buy and then I will determine on if it's my brand new alternator Bosch alternator I got is defective or my Bosch battery in the trunk or the Mercedes battery underneath the hood to auxiliary battery or my voltage battery regulator located in the trunk, for the most part I checked my computer's my Sams all nice and clean and brand new looking then inside the car underneath the car is extremely clean not a speck of rust was always stored hardly driven in the weather

 

Difficult to say...my experience was a wild ride. I changed the aux battery, the trunk battery, relay on aux battery, bcm, VR, alternator, and nothing helped the fix until I bought a used front SAM (driverside fuse box in engine bay) and it got fixed. However, there was a penny stuffed in the cigarette lighter that keep blowing the fuse. Good luck.

 

Why was the reason it went bad did it get wet ? Thanks

 

I'm going to check my batteries tomorrow the loads on them and then while it's hooked up I'm going to check my alternator and that checks out and then I'mma check my voltage regulator load regulator that's in the trunk change that out and if that still don't work but I know it's the same underneath the hood but before I replace that I'm just going to pay 200 for a shop to tell me exactly what it is

 

No, didn’t get wet. It could be a combinations of running battery for a prolonged period without charging and a short fuse (penny in cig lighter) that burns out the front SAM.

 

Ahhh ok than maybe this is my problem, just wish I had the coad reader to direct the problem , thanks you all vary,much for the feed,back 👌

 

I had similar issues, ending up changing he aux battery, main battery and alternator to solve it haha

 

Mines fixed! Changed out the whole alternator with a brand new bosch unit.

 

Hello everyone I have a 2011 e350 I have it for three years now, car would not start all light are on radio and windows work my dad jumped started the car everything seemed fine needed gas bad but was scared to turn the car off while pumping so I left it on drove home fine a few hours later started the car now I have a big red battery icon and a check engine might be due to fueling while running and the steering wheel will not move the car is running now the wheel is stuck can anyone help