Stop Start Consistency

[geraldrobins]

I like stop start but find it inconsistent in its application. Yes I know it depends on battery charge and temperatures etc.
Coming home today 35 miles ambient temperature 16 degrees C, engine temperature 92 degrees and it didnt work when I pulled up at a set of lights. On other occassions when its been not as warm, either outside or the engine, and it has worked. Sometimes it works after only a few miles from start up. Do other members experience the same?

I have started recording data now to advise MB when next in for a service unless I take in it before under warranty.

 

[Colin_b]

I have to agree. My C250CDI is completely unpredictable.

Aircon on, around 20 minutes/15 miles minimum to activate, sometime 100+miles.

Aircon off, activates within a mile to about 15 miles. Doesn't seem temp sensitive.

The time it will support the engine off varies from about 30 seconds to 5 minutes.

Completely inconsistent, varies wildly from day to day on an identical journey.

Dealer says no errors, so it is working as designed.

 

[gbjeppm]

It may have been a DPF regeneration, that also stops it working.

 

[geraldrobins]

Yes but how often does regeneration occur? Today wasnt a one off.

 

[Dieselman]

Are you modulating the brake pedal pressure enough to ensure it kicks in?

I find it very reliable in operation with only battery charge making any real difference.

 

[Ted]

Similarly, the only time mine played up on the Kia was when there was an issue with the battery.
Since a new one was fitted it has become entirely predictable, however there are things that can catch you out - air directed to windscreen only or aircon on and fan full speed disable the stop start.

 

[Colin_b]

Are you modulating the brake pedal pressure enough to ensure it kicks in?

I find it very reliable in operation with only battery charge making any real difference.

Certainly am, the green eco light is an accurate reflection of it being enabled.

I'll have to do some more research on the ECU values.

 

[panason1c]

Worth mentioning that during the time that the aircon is operating the stop start function is deactivated.

 

[geraldrobins]

Thanks for the responses.
I usually use the hold function when stopping and have tried different pedal pressures. I dont generally use aircon.

 

[theogeor]

On our 2011 A160 petrol manual is very consistent. Only few times it did not switch off since we bought it and was either too hot and A/C had to work or after too many start stops in short time which means battery condition was beyond threshold.

Theo

 

[baxlin]

Worth mentioning that during the time that the aircon is operating the stop start function is deactivated.

Is that general? I have my aircon on "auto" all the time, and while not 100% consistent, the stop start usually works fine. The car is a 2013 C220 manual.

 

[Colin_b]

Is that general? I have my aircon on "auto" all the time, and while not 100% consistent, the stop start usually works fine. The car is a 2013 C220 manual.

Aircon does certainly seem to impact start/stop. Doesn't disable it, though.

 

[daveenty]

Mine seemed to work all day today and this is unusual. I very seldom see the ECO light in green.

Having said that it's been warmer today so no heated seats or other heavy battery usage like lights and wipers I suppose.

As for air con, mine is never switched off, the only thing I tend to adjust is the temperature control.

 

[geraldrobins]

Well it worked fine today. After 20 miles on the motorway early this morning temperature only 5 degrees, engine temp 90 degrees, headlamps the stop start was working as I stopped at a junction. This afternoon it was ok and working after 2 miles with an engine temp of 60 degrees. Ill keep monitoring and try not to get obsessive.

 

[gbjeppm]

From the manual of the W166:

Automatic engine switch-off

If the vehicle is braked to a standstill in D or N, the ECO start/stop function switches off the engine automatically.

The ECO start/stop function is operational and the ECO symbol is displayed in green in the multifunction display, if:
the indicator lamp in the ECO button is lit green
none of the off-road programs are selected
the outside temperature is within the comfort range
the engine is at normal operating temperature
the set temperature for the vehicle interior has been reached
the battery is sufficiently charged
the system detects that the windscreen is not misted up when the air-conditioning system is switched on
the bonnet is closed
the driver's door is closed and the driver's seat belt is fastened
If not all conditions for automatic engine switch-off are fulfilled, the ECO symbol is shown in yellow.

 

[gbjeppm]

the set temperature for the vehicle interior has been reached

This suggests if you are not using Auto air conditioning mode, it is likely to not switch on.