2016 - E550 - Eco Start/Stop Not working
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Joined: May 2018
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2016 E550, 2018 GTC
2016 - E550 - Eco Start/Stop Not working
So - first off, not the WORST thing in the world. 
but trying to figure out the cause here. iI stopped quite a few months, maybe a year ago..? But nothing else is affected that I've noticed.
The Eco button still lights up green, turns on/off when I press the button
"ECO" is NOT displayed on my gauge cluster in any colour at all.
- I've got no codes thrown/stored
- Haven't seen the "auxiliary battery" warning on the cluster
- HOLD function still works
- Distronic/lane assist still works.
Side issue but possibly not related - I also don't know where the mysterious Auxiliary battery is. My regular battery underneath the hood. And I tore too much of my trunk apart to be have not seen it hiding in there somewhere. I've been reading there's a battery in the drivers side dash, but what people are pulling out of there are on older vehicles and doesn't match up with the smaller AGM battery that I've seen listed under my car in the Rockauto parts catalogue.
Any thoughts?
but trying to figure out the cause here. iI stopped quite a few months, maybe a year ago..? But nothing else is affected that I've noticed.The Eco button still lights up green, turns on/off when I press the button
"ECO" is NOT displayed on my gauge cluster in any colour at all.
- I've got no codes thrown/stored
- Haven't seen the "auxiliary battery" warning on the cluster
- HOLD function still works
- Distronic/lane assist still works.
Side issue but possibly not related - I also don't know where the mysterious Auxiliary battery is. My regular battery underneath the hood. And I tore too much of my trunk apart to be have not seen it hiding in there somewhere. I've been reading there's a battery in the drivers side dash, but what people are pulling out of there are on older vehicles and doesn't match up with the smaller AGM battery that I've seen listed under my car in the Rockauto parts catalogue.
Any thoughts?
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From: Toronto & California
2015 ML400 4MATIC, 2016 C300 4MATIC, 2014 E350 4MATIC (Totaled), 2006 E350 (Sold)
Main Battery issue most likely for ECO issues, get the battery tested at Autozone or if in Canada, PartsSource to check CCA (Cold Cranking Amps). Aux battery is under the trunk floor on the passenger side.
Thread Starter
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2016 E550, 2018 GTC
Nice - thanks folks! I haven't had any other battery related issues yet from the car so will just hold off on replacement for a bit. Any chance a trickle charge will bring it back?
And not that this is urgent now , but there isn't an aux battery in my trunk from what I could see. I had everything torn out and started even taking out things going down into the 1/4 panels/lights areas.
And not that this is urgent now , but there isn't an aux battery in my trunk from what I could see. I had everything torn out and started even taking out things going down into the 1/4 panels/lights areas.
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
helping yourself...
> Have you seen the voltage output from your alternator?
In case you don't know how to open the voltage didplay menu, you can just listen to the front windows winding up!
The window sound will examplify what the voltage supply is like in your car.
If it's smooth voltage supply is steady.
Repeat with both windows at the same time: sound and operation should remain steady and smooth.
If it sounds laborious, it's low Voltage under high Amperage.
> Floating your battery is always a good idea to keep system amperage down. Normally this is unnecessary if the car charging is operating correctly... check for yourself!
✌️
Last edited by CaliBenzDriver; Mar 31, 2022 at 06:20 PM.
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From: Dallas-Ft.Worth,TX
2016 E350 Sport
A trickle or conventional recharge will restore the battery, and the Stop/Start should resume.
My 2016 has the Aux battery in the trunk, but it has nothing to do with the ECO Stop/Start.
My 2016 has the Aux battery in the trunk, but it has nothing to do with the ECO Stop/Start.
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Thread Starter
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2016 E550, 2018 GTC
Battery was manufactured June 2015 - so close to 7 years old now.
I got it on the trickle last night, so lets see what it looks like tomorrow when I take the car out for a long drive.
I got it on the trickle last night, so lets see what it looks like tomorrow when I take the car out for a long drive.
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2015 E350 4Matic Wagon, 2018 GLE350 4Matic
I prolonged mine with a trickle charger, but you're just delaying the inevitable. Eventually I got more electrical gremlins, warnings in the dash, driver door module lost connection and none of the switches worked. All went away when I spent the $200 for a new main battery. Save yourself the hassle and replace it, you've gotten your money's worth out of that battery.
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2016 E550, 2018 GTC
Did the trickle charge and a couple of longer drives. Still no ECO mode. 
As I'm not see any other issues, and don't really miss ECO at all, I think I'll hold off on anything further and keep an eye peeled for those gremlins that may show up.
As I'm not see any other issues, and don't really miss ECO at all, I think I'll hold off on anything further and keep an eye peeled for those gremlins that may show up.
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Actually, I had blown a fuse for the 12V accessory outlet (i.e., cigarette lighter outlet) and the ECO Start/Stop quit working until I replaced the fuse. Then I paid $150 to have it actually turned off. Go figure.
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W212 FL
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From: Toronto
2020 E63S & 2016 E550
Hard to change the main when the car starts like a champ but I think this will be good insurance. Did you ever find your aux battery?
UPDATE: changed the main battery with an H7 AGM from Costco and now ECO start stop works again. 12.84V
Last edited by GTA_S6; Feb 12, 2024 at 08:43 PM.
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2008 E350, 2012 ML350, 2014 E350, 2015 ML350
Really good of you to close the loop on this thread! I have a 2016 550 as well (Canada) and my ECO has not worked since this summer. My main batter is 12.41V max after I put it on a good charger so I know it is going downhill. I too could not find my aux battery after watching all of the videos of where it was 'supposed' to be as I wanted to test that voltage as well.
Hard to change the main when the car starts like a champ but I think this will be good insurance. Did you ever find your aux battery?
Hard to change the main when the car starts like a champ but I think this will be good insurance. Did you ever find your aux battery?
1 - either the mid-sized battery in the trunk next to the spare tire, nor
2 - the small size battery behind the dash
correct?
MB loves to hide their auxiliary batteries. In some cars, like the S class, and ML class the batteries are hidden in the trunk side pod. You can try looking with a flashlight around the right side pod in the back around the RearSAM.
NOTE: the 2016 E550 was sold in the US, but in Canada.
Also, there is a "third king" of "auxiliary battery" which is a large capacitor sometimes hidden around the main battery up front (as they did in some W211 for the SBC), or in the passenger footwell (as they did in the GLC 300).
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Most battery threads indicate that getting the correct battery from the dealer is not much more expensive, if at all, than from a local parts store.
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2020 E63S & 2016 E550
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https://www.mbpartscenter.com/oem-pa...Y4LWdhcw%3D%3D
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W212 MY'14 M276-3.5NA @75kMi
amazing upgrade...
I think at some point MB vendors nailed a better design.
They converted the good AUX AGM into a module stuffed with 4 or 5 capacitors of 1Farad.
When that module gets stressed, it chacoals its PCB... no repair! Unlimited currents cooks all.
New unit only (not used!)
Located at front passenger footwell, yes?
The question becomes : How To Prevent Killer Currents?
- test for disfunctional yo-yo voltage
- clean GND including main strap.
They converted the good AUX AGM into a module stuffed with 4 or 5 capacitors of 1Farad.
When that module gets stressed, it chacoals its PCB... no repair! Unlimited currents cooks all.
New unit only (not used!)
Located at front passenger footwell, yes?
The question becomes : How To Prevent Killer Currents?
- test for disfunctional yo-yo voltage
- clean GND including main strap.
Last edited by CaliBenzDriver; Feb 6, 2024 at 03:53 PM.
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2008 E350, 2012 ML350, 2014 E350, 2015 ML350
I think at some point MB vendors nailed a better design.
They converted the good AUX AGM into a module stuffed with 4 or 5 capacitors of 1Farad.
When that module gets stressed, it chacoals its PCB... no repair! Unlimited currents cooks all.
New unit only (not used!)
Located at front passenger footwell, yes?
The question becomes : How To Prevent Killer Currents?
- test for disfunctional yo-yo voltage
- clean GND including main strap.
They converted the good AUX AGM into a module stuffed with 4 or 5 capacitors of 1Farad.
When that module gets stressed, it chacoals its PCB... no repair! Unlimited currents cooks all.
New unit only (not used!)
Located at front passenger footwell, yes?
The question becomes : How To Prevent Killer Currents?
- test for disfunctional yo-yo voltage
- clean GND including main strap.
Guess you referring to the one above, like used in the GLC300. Here is a video as it is installed in the GLC
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
yes, exactly! That's the new virtual lead-free battery. 
My 2¢ says you don't need to mess with the side carpet or the plastic threshold piece.
Go ahead have a look, I recall the footwell carpet pulls back from the top.
Of course one can remove everything out carefully, replace the broken plastic threshold pieces, roll the carpet nicely...
or take a quick shortcut.
My 2¢ says you don't need to mess with the side carpet or the plastic threshold piece.
Go ahead have a look, I recall the footwell carpet pulls back from the top.
Of course one can remove everything out carefully, replace the broken plastic threshold pieces, roll the carpet nicely...
or take a quick shortcut.
