The complaint was that the dishwasher would not drain. When I looked underneath I saw that the solenoid piston was covered in some kind of hard black goo. You can see it on the shaft sticking up from the old solenoid in my hand.

I do not know where this stuff came from but it kept the solenoid from pushing the piston up which keeps the unit from draining. You can see the shiny new solenoid assembly installed too.