Boy do I feel stupid.....When I topped off the fluid the other day, I filled it, with about 2 cups of fluid, saw it was full, put the cap back on and still thought it was the low fluid sensor. Well, I just returned from "topping" it off again, but this time I waited about 15 seconds and noticed the level slowly dropping, I again topped it off......I did this for almost a gallon. I pulled the filler neck off of the hidden bottle and noticed that the filter screen was getting clogged and only allowing a little fluid in at a time....So all along it wasn't the sensor.....it was the pourer (me)......the simplest is usually the most obvious........

(But, I don't think I'll tell my wife.....because I'll hear it forever, aka, married 30 years)