blynaslt

Hello all, I have W221 S500 2006 VIN: WDD2211711A005110 and I am having problems with the A/C system, getting code "9315 A9( AC Compressor) Pressure Control Valve Short Circuit To Positive or Open Circuit"

I have looked at the SAM on the driver's side and saw that there is only one wire going to the AC Control Valve Number 8, I have checked the wiring diagram and I see that there should be 2 wires coming to the valve, connected the number 9 wire from the SAM to the positive side of the Valve but still having the same message.


I went to my local garage which deals with A/C and they are telling me that MB uses only one wire for the A/C Compressor control valve and that he tested it and it seems good, now I am completely lost.

My first question would be if there should be 2 wires going to the A/C Control valve or only one?

Is there any way to test the Control Valve by resistance?

I also read that this could be caused by a blown diode which causes inductive currents from the coil in the valve of the a/c compressor to reach front SAM.

Thank you in advance for the help.

slick65

I'm having the same issue in my 2008 S63

blynaslt

For me personally it was the solenoid, but changed to a new compressor cause old ones bearing was shot.

slick65

So a solenoid change is an option?

I see itvis very tight quarters

Beka_Karumidze

In my case it was a diode issue, you would need an oscilloscope to see it



All below 0 line is reverse current causing controller to stop signal and log AC copressor short circuit code