Thank you for your generous help.
I removed the ECS sensor and cleaned off what looked like a little tiny bit of some residue of mashed potatoes. I also removed the other black plastic sensor next to it and cleaned it too. So, this brings up 2 more questions.
First, should we be sure that all plates, etc. are completely rinsed off before going into the dishwasher, to avoid this in the future? Second, do you think that I need to take the inside bottom sump section apart, and clean that too? There was barely anything inside where the sensors are at.
Your help was greatly appreciated.