W212 Airmatic wiring diagram

[Ettcon]

Hello MBsters
As my S212 Airmatic discharge valve does not work anymore (you know the one mounted on the airmatic compressor), I would be happy if someone could provide the electric diagram of Airmatic. It probably includes the Airmatic ECU under passenger floor and all the level sensors, damping actuator and valves. Thanks in advance.

 

[mersum1es]

Sorry no diagram, but have you checked obvious; fuse, relay, wirings near compressor/connecting plugs, height sensor linkages?

 

[Ettcon]

Sorry no diagram, but have you checked obvious; fuse, relay, wirings near compressor/connecting plugs, height sensor linkages?

Thanks. Yes, all visually checked, now I need to check the cable going from passenger floor to the compressor and I'd like to find the polarity, but the cable is only written 1, 2....

 

[mersum1es]

Easiest way it get it plugged on SDS, you immediately see if there are real fault codes, and then you can actuate one function per time plus do performance test to compressor. Rarely there is any other problem in wirings than near compressor unit (where they wear/broke very often). A broken wire of release valve alone can prevent unit engage. Sensor wires also fail rarely, like sensors itself, but linkages broke/fall off often.

Well hopefully someone with access to WIS prints electric diagram to you (my SDS computer is not and will never be connected to net so sharing stuff there is bit awkward).

 

[Diesel Benz]

Diagram attached but I'd suggest checking the wiring next to the compressor as suggested above. Sometimes the discharge valve itself misbehaves.

 

[Ettcon]

Easiest way it get it plugged on SDS, you immediately see if there are real fault codes, and then you can actuate one function per time plus do performance test to compressor. Rarely there is any other problem in wirings than near compressor unit (where they wear/broke very often). A broken wire of release valve alone can prevent unit engage. Sensor wires also fail rarely, like sensors itself, but linkages broke/fall off often.

Well hopefully someone with access to WIS prints electric diagram to you (my SDS computer is not and will never be connected to net so sharing stuff there is bit awkward).

Indeed, you are very correct. This is exactly what I did. My SDS returns the "open circuit" C153xxx error. So I'm currently checking the two wires (GREY-RED and BLUE-GREEN) from the back of the care to the front N51 AIRMATIC ECU. So far nothing broken around the compressor outside and inside near the reservoir. Another day tomorrow to reach ECU and learn if it is a story of cable or a dead ECU driver transistor.

 

[Ettcon]

Diagram attached but I'd suggest checking the wiring next to the compressor as suggested above. Sometimes the discharge valve itself misbehaves.

Thank you very much. This is helping a lot ! Wiring seems ok around compressor, but probably dead someplace else. Investigating !

 

[mersum1es]

You have SDS? So you have all electric diagrams AND functional ones too in WIS!

 

[Ettcon]

You have SDS? So you have all electric diagrams AND functional ones too in WIS!

Sorry. No I don't have specifically SDS. I have Youcanic. I realize now SDS refers to Star Diagnostic. I thought it was a generic name.

 

[Diesel Benz]

My SDS returns the "open circuit" C153xxx error.

Which exact fault code? The C153xxx fault codes seem to refer to the Airmatic valve or the adjustable valves on shocks, not the valve within the compressor.