Bosch water valve(dishwasher)?

I have a bosch dishwasher(don't know model#) its 10 yrs.old, the valve that controls the water inlet does not open up to let the water through.I checked the valve and it seems to be working,the water valve is in the open position.I am wondering if there might be problem with the diaphram that is inline with the solenoid valve,when I checked for power ,I get the proper voltage across the solenoid valve contacts.Could you help me out