Siemens dishwasher check water supply light?

Help, my Siemens SE25M851GB/35 is malfunctioning. It stayed on a constant cycle and filled with cold water, and the water supply light came on.
I have done the following to no avail:
1. Reset the machine....water drains away ok
2. Had plumber check water supply and waste supply
3. Took off and cleaned water pump cover

Then when I start a cycle, the water supply light comes on after a few minutes and the time does not diminish.
I have 2 small children and need to fix it. Any ideas?
Any help appreciated. Karen