Problem on CNC Bosch CC220

Guys,
I got a prblem on CNC, and could no t found a answer on my manuals.

When I switch on the controler on screen shows X=0/Y=0, I switch on the Driver and when I try do the reference, the screen shows an error: Traverse to Reference Point Start Axis! If I prees the button Y+&X+ the massage change to: Reference point traverse.
How I solve this problem??
More, everytime that I switch on the the value measured X/Y=0. I switch off the Driver and move the axis manually on the screen the value from X/Y change, this showme that sistem of measuring is ok!

Someone can help me???