Motif XS Volume faders control Cubase

Does anyone know, is it possible to set up a Motif XS to control Midi CC message in Cubase using the Motif XS 8 volume faders?

I can Midi Learn the Knobs, but not somehow the faders …

Hi,

Make sure, Assignable Function 1 or 2 is switched on (the LED close to the faders is on).

Thanks Martin - I press those buttons, but no light comes on …