[JRTJH]

Most of us have stopped relying on the tank sensors for anything other than a bunch of red lights with no purpose. With use, you'll learn what your toilet sounds like as the tank fills and you flush. Most owners can tell you when they dump, either by "we get X days between black tank dumps" or "When I start hearing that little gurgle when I flush, I know it's time to dump"....

There are some people who do use their tank sensor system, they are the "lucky few" with an operational system. The rest of us, our system gave up being "honest" years ago.... YMMV