The most important is if the CSS is pushing the rod and it has enough power to keep it pushed out. It is just 12V simple solenoid, you can try it with jumper wires to see if it works.
I have recently bought the brass adjusting nut, the rubber seal that goes on the rod and the black wire connector (just to make it look nice) at Mercedes Benz dealer with no issue. Make sure that the cut at the end of the rod for flat screw driver is clear. Make sure the adjusting nut and the counter nut turn on the rod freely (saves blood and sweat while adjusting).
I have also cleaned my CSS and repainted it. I have seen it yellow plated colour on most pictures, but I have seen it in different colours too (steel, black, etc.).
The CSS is activated when ground is delivered to it from hydraulic switches on the sides of the gear box - one for D, one for Reverse. In the Technical Manual you will see that it is powered from fuse No.5. Then ground, as I said, comes from those switches. You can see how these switches look like in the Technical Manual - on the same drawing where you have wiring and on the last picture of the gear box - the switch is over the label "22mm locknut". Other switch is same place on the other side of the gear box.
I modified the post as I thought the part numbers may be a bit hard to find for the MB "not Pagoda educated" dealer:
Adjusting nut A1309900050
Rubber collar A0019970681
Connector A0005467041
In the EPC they are under Engine, 07 Injection pump, 001 Injection pump.
The above is for Europe. I am not sure if US version cars had the same solution and had these switches on the gear box. CSS was used for AC as well. Someone told me constant speed while gear selecting was achieved by emission control system, but I am not sure about it. If it is true, maybe this system is not working properly - but again, I am not so familiar with the US versions.
If you need further details on the wiring, let me know, I will PM you.
