Functioning of Start-Stop Merc E220

[MaxNg]

I've been running a 63-plate E class 220 for the last year.

Prior to the last maintenance in October, it seemed that it took a long time for the ECON green light to illuminate, indicating that start-stop was operational. Mercedes Perth said this was due to my doing a lot of short journeys; however, even on >50 mile trips, this system occasionally still wasn't functioning - ie, the indicator light on the speedo not going green. They also said that this system has an independent battery that needs to be at a certain charge level and I since have found that the system can be brought on-line by "load-shedding": e.g., turning off the blower, heated rear screen etc.

Out of interest, can anyone here enlighten me what really are the various parameters for this system to operate?

BTW, other than this minor matter, this car has been flawless.

[tonys]

I can't recall all of the parameters but there are quite a number. One is aircon, ie can car maintain set parameters of aircon if the engine is off. Others include engine temp, demand on battery (drain) if engine is off, actual battery voltage. I think external temperature is a factor, but not sure. Anything in handbook (can't be bothered to get mine ).

Personally, I'd prefer if it defaulted to 'off', rather than on, or if you could disable it via the menu function.

[Dog Star]

tonys said:

Personally, I'd prefer if it defaulted to 'off', rather than on, or if you could disable it via the menu function.

Agreed - however they wouldn't get the emissions claimed without it, I believe.

I found it very intrusive on the two SLK250 diesels and my E220 CDi coupe. I've got a new identical coupe but the 200 petrol and it's much better on that - there's not the characteristic diesel shudder on startup.

[daveenty]

MaxNg said:

Out of interest, can anyone here enlighten me what really are the various parameters for this system to operate?

From a (US) manual I acquired online: -

Automatic engine switch-off

Method of operation

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

The vehicle is stationary.

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 windshield is not fogged up when the air-conditioning system is switched on

The hood is closed.

The driver's door is closed and the driver's seat belt is fastened.

If conditions for automatic engine switch-off have not been fulfilled, the ECO symbol will be shown in yellow.


The critical ones seem to be battery condition and temperature so, at the moment, it's going to take a while before anything happens.

tonys said:

Personally, I'd prefer if it defaulted to 'off', rather than on, or if you could disable it via the menu function.

The AMG version does, or at least is switchable and stays off when switched off.

[MaxNg]

Thank you for these responses. The system is switchable on my car too (Not AMG) by the green-lit ECO switch. Now that in NE Scotland we are up to a balmy 8 degrees, I saw that the system came active rather faster this morning than when it was sub-zero a few days ago

[Smokehead]

My E220 displays exactly the same behaviour. Basically when the weather is typically Scottish, the green Eco symbol rarely comes on.