Soryy, I cheched today the steering angle sensor agin. Now I can see the signal graph in the MES data window when I turn the steering.
Maybe I made yesterday something wrong in MES settings.

My Ducato 250 Display show up some failure , like .... Hill Holder , ESC not availabale. I made with the MES the calibration of the longitudinal /lateral acceleration sensor and for the steering angle sensor. After those calibration procedure I can see the graph diagram in the MES parameter function...