andyberesford

Hello All,

I have a 2015 E350 AMG Line premium (UK), recently purchased.

When I got it ECO (Start / Stop ) did not work all.
The selling dealer replaced both the main and auxilliary batteries and told me it was fixed.

It is now fully working so long as air/con is switched off.

When you switch air con on it mainly does not work, sometimes it comes on (GREEN ECO) for a few miles and then goes off.
If I switch Air Con off it functions great.

Been to my local garage and then cannot find fault,
Anyone any ideas as I am loathed to pay MB £108 per hour diagnosis.

Thank You

cotmfk

FWIW, a lot of people "complain" (not sure if that's the right word) that the start/stop function is very finicky on their cars.

I almost never use mine. The only time I am in Comfort mode for the motor is when I am on a long highway trip. In my experience, the green ECO light does go on and off during those trips. My impression is that it stays on more than it doesn't, however. Also, I usually forget to turn it off when I exit the highway, and it will turn the car off when I reach the end of the offramp as I stop to see traffic before making my turn onto the side road. I need to do a long highway drive strictly in "S" to see if "C" actually nets any gas mileage savings. I can tell the difference between the throttle sensitivity in C vs. S, so I believe it has to net some sort of MPG savings.

I personally prefer to leave ECO off, as I have read some information that the motor has to be off for at least 30 seconds for there to be any savings in MPG. That may or may not be accurate anymore. I generally find that I am stopped for less than 30 seconds at a time, with the only times being stopped more than that is if I happen to hit a red light just as it's turning red.

AMGfifty5

Not sure if this related. But I was told that one sign of a failing brake vacuum pump is the a/c not working.

Dealership told me to replace mines but I haven’t gotten to it yet as I’m not experiencing any issues.

mbwillgrubs

See attached for the MB version of what it is supposed to do. I have the same experience as some other posters. The A/C issue may be related to the system not shutting down when there is the potential to make the passengers uncomfortable. There are certain temperature ranges where the system will not operate. You could see if it were too hot or cold it would keep the engine on even if the system were enabled (green eco light). I can go into settings and disable the start/stop feature but still retain the comfort mode. I think shifts are different, not sure about cylinder cut-out but I do notice the throttle response is different. A lot more throttle is needed for a particular acceleration. The system is probably just smoothing the throttle response for comfort. Best

andyberesford

Thanks for the responses and info.

I think it climate related as it is starting to work more as it gets a bit warmer here in the UK

wseikow

Battery and weather conditions affect the operation of this feature.
If it's the middle of winter , it wont typically operate. In other words, it operates as inteneded.

Consequently , in the middle of summer, if you are using AC, rear defrost , cooled seats... and your battery is not in top shape , the Eco feature may not work.
Again, as inteneded.

Rehabguy

Agreed with above comment. This feature only goes into effect if a series of factors are met. Otherwise it won't shut off your car. Personally, I feel this feature is more of a nuisance than anything. First thing I do after the car is on is to switch to S.