Black tank sensors say full when empty

No, you can’t “reset” the sensors. Most likely, they are dirty and just need to be cleaned off. This is a super common issue.

Here is a link explaining exactly how to clean out your black tank step-by-step and maintain it to keep the sensors clean and prevent it from ever clogging: https://camperfaqs.com/how-to-clean-out-rv-black-water-tank

Tank sensors are notoriously inaccurate and fail constantly. I don’t trust them. I look down the hole with my phone flashlight to see how full my tanks are (not an option for everybody). Some people can tell by the sound, the fuller it gets the closer the “splashing sounds.