Siemens SX65E001GB Dishwasher Erratic Operation?

We have a Siemens Integral Dishwasher which either doesn’t start or stops mid-cycle and in both cases the “Check Water Supply” and “End” LEDs are lit. The water pressure seems fine.
I have cleaned the main filter and filters on the incoming supply and on the waste pump. My “Volt-Stick” shows there is mains voltage being applied to the incoming water solenoid in the supply hose.
Looking at other forums I wonder if this model has a metering hose inside that maybe blocked. If so, how is the hose accessed? I assume that this is somewhere on the drain.
Many Thanks