Recently I bought a 2014 E250 Cabriolet. I just love the lines on this car and pretty much everything about it, EXCEPT the start stop function automatically turning on. I live in a rural setting with relatively light traffic, so the need for this functionality is just not there for me. I therefore decided to turn it off.

Scanning the the various websites uncovered many people in a similar situation, where they just wanted to turn it off. But it seems the solution is not simple. Well I have found a solution which is easy to do and will cost you NOTHING!

i will explain what I did and for those of you with other models, you should be able to work it out.

I first got the fuse diagram for my car (found with the spare tyre in the boot) and looked up start stop. This had 3 fuses associated with it, however 2 of those fuses were used by other systems. One of the 3 fuses was ONLY used by start stop, number 91 in my case. I pulled out this fuse and BINGO, no more eco start stop! No check engine light either!

I taped this 10 amp fuse upside down in its normal slot so that I can reconnect the system if I ever need it.

Hope others find this useful.

Great to know - thanks!!!

Why do you think it odd? It is not st all unusual to protect circuit wiring with fuses. Sometimes a fuse will protect just one circuit. Sometimes a fuse will protect more than one. In this case, it appears that fuse 91 only relates to the start stop circuit. Nothing *odd* about that at all.

i have a 1500km run in the car over the next 2 days. Will see if anything unexpected turns up.

cheers

“Odd” perhaps the wrong word. Just unusual in my experience for a fuse to protect only a single circuit in a car. Again, how do you know that this fuse protects ONLY this single function? Are you certain that removing it does not turn off some other function? Randomly pulling a fuse without fully understanding the circuit(s) controlled by it seems foolhardy, especially considering the complexity of the electronics in today’s cars.

Just completed 650km highway and 80km stop start city. Didn’t miss a beat!

Ran the scan tool over the OBD port and no system errors.

Nice

Judge, you need to remain unemotional and objective .

I wonder if the fuse number would be the same for my 2017 & 2018 mb?

I explained exactly how I referred to the vehicles fuse schematic to determine which fuses were involved in the stop start system and then logically determining if a single point system fuse existed. By using that logical approach, one could identify the best candidate for interrupting the circuit.

Judge said that I had been “randomly pulling fuses”. Where did that come from? That process was not used in this case. The process I used was logical where candidate fuses were first identified and then analysed. To me, using that phrase, followed up by the suggestion the approach was “foolhardy”, was a sign of an emotional response, aimed at discrediting this work.

Enough on that. So far the car is operating exactly as it was before, but without the ECO light and stop start function initiating on start up. I will be covering another 700km or so again today and will report back my findings, but this is behaving exactly as expected and looking pretty good right now.

cheers

You would have to firstly check your fuse identification map that in my vehicle is stored with the spare tyre tool kit. It is important that you are clear on which circuits are impacted by any candidate fuses.

regards

Yes it does. As does Distronic, Speedtronic, lane assist etc.

cheers

🤣🤣🤣🤣🤣🤣🤣

In my 2014 E250 Cabriolet, fuse 91 is located in the trunk, on the fuse panel next to the auxiliary battery. It is a 10 amp (red) fuse. I will try and get some pics up later today.

cheers

Pic of relevant fusebox in trunkbelow...


Fuse 91 (circled) is located neat the centre of the fusebox
​​​​​

Completed another 700km mixed highway and city driving yesterday. Car continues to operate as normal.

And just a heads up, some markets may have the fuel filter heater also on this circuit. This might be of interest to those that experience very very cold winters. Does not affect me as my minimums never get below -20 deg C.

Cheers

Pretty amazed you don't think -20c is cold! Not sure where you live but I live in Canada and we think that is pretty cold around here!

Hey Mike. -20 is cold alright. You guys really know what cold is about. Oh and the Russians too of course! 😁

Just an update. It’s been 6 weeks now with this mod and the car continues to perform properly. I have forgotten all about the eco button now...

Basically correct. The circuit also supplies power to the filter heater element to keep water in the filter from freezing in v cold temps. I had a look around and seems temps less than about minus 5 or 10 deg C with diesel could result in ice formation and possible fuel restriction to the engine if there is water in the fuel. What winter minimums do you get? Is the car garaged? Do you get good quality fuel? These are the questions that will give you an idea as to whether or not to pull the fuse. If affected, Maybe just replace the fuse for dead of winter. It’s easy to try, and is reversible.

My local temps never get that low so no issue. Hope this helps.

cheers