When you start the dishwasher what actually happens?
Is the drain pump running all the time?
Will it put any water in the dishwasher at all?
Ok what you can try is pull the dishwasher out and tip it backwards and see if anywater comes out from the bottom. I don't think this is the fault but worth checking as when you get the water tap light on its either water has leaked into the base and activated the flood switch or the impeller jug (flow meter) is faulty. It can also be the control board but more often its a leak or the flow meter.
If its not water in the base then remove the left hand side panel and you will see the flow meter at the back . Its round and will have to hoses going to it. One from the fill hose and the other to the plastic filling tank on the side.
Replace this flow meter and that should cure the fault. As these flow meters go faulty a lot on Bosch. We replace loads of them.
Ok I didn't think there would be water but was worth just checking anyway.
For the flow meter click here.
Your very welcome. Have a good one yourself whats left of it.
Also if you haven't already if you could rate the answer that would be great.