In the tank, there is a float that is attached to a rheostat. The rheostat sends a voltage signal to the PCM which goes to the BCM and then to the gauge. Ugh! A lot of things there.
I suspect the rheostat is bad or the float is going bad, However, If you look through the attached pics, they indicate the diagnostics for troubleshooting the issue.
Let me know if they help or if you have other questions.
Images (Click to enlarge)
Wednesday, December 2nd, 2020 AT 7:24 PM