Hello again.
I'm surprised a lot that there's no speed signal from the ABS control unit. Even CD30 have that speed dependent volume feature and there should be a signal to support it.
Anyway, we can talk about this later, but first the information you think you need : ABS/ESP control unit is inside the engine compartment, behind and left to the battery. It is under the ABS hydraulic pump as you'll see on the drawing attached. The pump and the control unit are sealed together so you may probably need to remove the whole thing to reach the control unit's socket. Pump is covered with a black plastic part and you'll need to remove it to see the pump.
For the 2010 model year, the pin number 3 on the control unit's socket should be wired to pin number 3 on the X1 connector and then pin 37 on the XC71 (main radio connector). If you really need to draw this wire by yourself you can of course skip the X1 and go to the radio direct from the control unit.
Hope this helps.
Cheers,
Serdar
[Blockierte Grafik: http://imageshack.com/a/img600/4231/jbku.png]