Eco stop start fault?

[VN1]

Hi

Wondering if someone can help with this. I have not owned my mercedes for very long and purchased it from a MB dealer.

When coming home from work in the evening I have noticed that the eco stop start switches on after just one minute of starting the car and driving. Going by the handbook it states once a bunch of conditions are met including one which is that the "engine is at normal operating temperature" the light will go green and stop/start will kick in. As the engine is not at normal temp (the needle is still on 0 degrees) I am wondering if this is a fault with the vehicle. I have contacted my local dealership however they have said that the oil temp heats up very quickly and it is this temp the system looks for. Is this true? My car is currently under warranty however I was told on the phone that if no fault was found I would have to pay the diagnostic fee of £120.

Note that in the morning it takes around 5 minutes or so to come on however I would have thought this being because some of the other conditions are not met.

Any help would be appreciated.

Thanks

 

[Markjames]

I am now on my second 220cdi with stop start, first one a c class and now and e class and they have both behaved as you have said. Sometimes it's green within moments of starting the car, sometimes takes a few minutes and sometimes it takes an age for it to go green. Think that's just the way they are. I did have to get my c class checked when still quite new as engine was cutting out on the stop start before it had stopped moving, it was only just before but enough to make it uncomfortable and felt a bit unsafe. This was sorted with a programme upgrade.

 

[developer]

Mine is very variable, deciding when and where to operate, with no obvious logic.

I'm sure, as a new car, it's operating properly.

£120 for a diagnosis on a car they supplied is a poor show IMO.

 

[ash59fifty-uk]

A bit different but our work vans (VW Caddy) have start-stop technology on them. A number of us would bring this same issue up with VW and they have simply explained... This technology kicks in under normal conditions, certain factors like heater use, stereo, basically using up energy can make it not work every now and then

I've tested this, music blaring during all journeys and heating on full power (during colder weather back in February/March) and what they say seems correct.

Soon as the weather brightened up, and stopped using the radio/entertainment the stop-start worked as normal Possibly the same with Mercedes vehicles?

Basically, the battery

 

[def90cars]

I have this on a couple of cars.

I think it is cleverer than me!

 

[Wheelsnuts]

I have experienced the same issues with my car which I have had for over a year. It always re-starts on cue so I guess it's just the way the technology works and nothing to worry about. The threat to charge a steep diagnostic fee is a bit off in my opinion!

 

[Red C220]

It can be hit and miss, we also found that having the A/C switched on substantially prolonged the time before the ECO light turned green.

 

[st13phil]

...we also found that having the A/C switched on substantially prolonged the time before the ECO light turned green.

In certain conditions having the A/C switched on can prevent the ECO Stop/Start operating at all.

 

[geraldrobins]

Mine is similar but note its colder in the mornings than when you leave work and the car has probably been left to cool down for longer overnight.

 

[olliesgrandad]

I find it is very 'hit and miss' as to when it works or doesn't. tends to cut in and out a bit too smartly for me compared with other vehicles i have owned. I tend to turn it off in traffic when i know i need to pull away smartly at junctions as i notice my car switches off as soon as I touch the brake when stationary (7 speed auto). Annoying when it keeps stopping and starting waiting at a junction when edging out.

 

[VN1]

Thanks for all the replies guys not really sure what to make of this start/stop technology. Sometimes I wish I could permanently switch it off. Cannot be good for a cold engine.

 

[geraldrobins]

Thanks for all the replies guys not really sure what to make of this start/stop technology. Sometimes I wish I could permanently switch it off. Cannot be good for a cold engine.

You can turn it off via the eco button.

 

[VN1]

You can turn it off via the eco button.

Sure but not permanently. So when I switch my car on again say later in the day it will come on again by default

 

[geraldrobins]

Don't think it can be done, alongside reverting to E mode on the auto change, which might be to do with the emissions and mpg tests being done at the default settings.
Incidentally mine was working within a mile of leaving home today, in a 30 limit, at 0720 but it was 15 degrees outside.
I like it but clearly not everyone does.

 

[smurph1]

Anyone ever get to the bottom of this...I bought a ~3 year W204 at start of winter and it stop/started all the time (in fact far too easily frequently if you ask me), and even in the colder conditions. Now it hardly ever does, and hasn't for a while, and still won't even now it being much warmer, am absolutely baffled??

 

[Headhurts]

Possibly the battery given up.


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[Mr Filipov]

Not faniliar with that generation C class, but if you have the mode selector and individual mode, you cna have it perm off. As long as the car will also re-start in individual.

 

[smurph1]

Thanks, but don't understand either explanation!

 

[Deleted member 126969]

I think start/stop can look random or plain daft simply because we have no way to find out exactly which parameters it asseses or what limits are applied to them before the start/stop will activate. Lacking proper info, all we can do is guess how we might design such a system. First priority is that it never lets the battery get low enough to risk it not being able to restart the engine. after that, you then worry about letting the engine warm up some before letting it kick in, you also worry about prediciting electrical loads at any given moment and then trying to predict just how long it will be sat like that. Plus all the things I haven't thought of 'cos I don't design cars.

Easy to see how it ends up looking like it runs on magic or random numbers even though it is following a strictly defined set of rules, although those are probwbly implemented through fuzzy logic for good measure.

On the C350e the start/stop works all the time (unless disabled by mode choice) but then it does have a chuffin' great battery sat in the back.

 

[smurph1]

OK, its just weird that mine has changed how it operates, and is now not working in warmer times, which I believe temp to be one of the parameters.
Anyway, as Headhurts tried to say, and you note, maybe my battery is under performing, and thus that could be a reason why its not working anymore....will investigate!