MortenJ

I have on my Mercedes-Benz E-class, W212 /E220CDI 7-Gears, model 2012, just got changed the air conditioning compressor as it had a defect. The weird thing is that the old, original one had a 4-pin socket for the wirings, while the new one – with the same part number 000830270080 - only has a 3-pin socket! It is a new equivalent original Mercedes air conditioning compressor. To solve this, Mercedes-Benz delivers a 4- to 3-pin adapter/connector, part number 2701505720.
The air conditioning system works again, but since the replacement of the airconditioning compressor my ECO start/stop system does not work any longer!!

I can turn on and off the ECO switch in the control panel and the green LED-indicator light in the switch turns on and off correspondently - and the ECO sign text in the speedometer switch on and off also as it should, but the ECO sign text in the speedometer remains yellow during operation, and will not turn into green as it usually does at normal engine operating temperature and allows the engine to stop idling when stopping and pressing the brake pedal and starts again when I remove my foot from the brake pedal.

My excellent Mercedes specialist workshop, who has installed the air conditioning compressor, has had the Mercedes-Benz STAR tester connected to the car, and there are no errors anywhere. There are "checkmarks" on all parameters. So it is reasonable to believe that there is a relation with the air conditioning compressor, since the ECO function error came simultaneously with the change of the air conditioning compressor.

It is Mercedes-Benz, who delivered the two original parts, and they tell us that it should be the right parts. However, both my workshop and I are wondering deeply what the "4th pin" of the plug had to be used for in the past- and now we obviously do not need it anymore. It is an obvious thought to believe that this 4th pin is supposed to send a signal that "now the ECO function can very well turn off the engine for the sake of the air conditioning compressor". But if the ECO function does not get that signal through this 4th wiring, this may possibly be the reason why it will not turn the engine off while stopping and pressing the brake pedal down.

And then the questions:
1. Is there anyone who has experienced similar corresponding error with the ECO function when changing the air conditioning compressor?
2. Is there anyone who has experienced changing the air conditioning compressor from a 4-pin model to a 3-pin model, including the associated adapter/connector- and the ECO function continues to function as it should?
3. Is there anyone who has a suggestion for solving my problem as described?
4. Is there anyone who can explain what the reason is for changing from a 4-pin plug to a 3 pin plug - and what wiring to the 4th pin is made for and have had of effect?

Any other good and constructive input to solve this problem is of course highly welcomed.

Plutoe

For clarification post you VIN!!

MortenJ

The VIN comes her: WDD2122021A561932

Plutoe

I made a mistake---post 5 is correct!!

konigstiger

EPC shows compressor 0032308711, plug 0535451528, see capture.

MortenJ

Thanks to both Plutoe and konigstiger.

I must admit that the part numbers you refer to from EPC seems to be correct in accordance to EPC. However, both 0032308711 and 0008302700 seems to be suitable for my car if you search around widely.

My workshop was informed from Mercedes-Benz that the part number should have been amended or updated, but why has Mercedes-Benz not updated EPC then (?)

Or, are we running with different set of part numbers in the US and Europe (I live in Denmark) - I doubt! It would be crazy.

Recent movement today is, that the workshop has been in contact with the Danish Mercedes-Benz importer to solve the problem, and they have a special testing procedure agreed to extract a lot of data from my car which they will send to Mercedes-Benz in Germany for analysis.

It is scheduled for August the 16th, and I will be back with an update later on.

Other views from other users are still welcomed.

konigstiger

EPC shows 0032308711 is for MY2012 (code 802), 0008302700 is MY2013 (803) which “may” explain pin difference

MortenJ

Good point. We are probably getter closer to the answer.

I will bring it for the attention for my workshop fellows.

Thanks!