No water on wash cycle

Question

I have a Bosch SMU 2000 series dishwasher . There is enough water for the pre wash cycle but once it gets to the wash cycle there is not enough water. If I put water in the bottom of the dishwasher it will wash good and then when the timer turns to the rinse mode there is plenty of water. I checked the screen on the inlet and it is okay, since there is only a lack of water on the wash cycle is it possible the timer is faulty.