My dishwasher is not draining all the way. I have heard that there is some kind my electric valve that pumps the water into the drain. Is that all I need to fix it?

Can you hear it running during the drain cycle?

If so, the problem is more likely goo buildup in the rubber or plastic drain line going from the d/w to the sink drain.

Disconnect it from both ends and run water through it to check it out as a start.