Yep, it is the sensor on the sending unit. It's a known issue for our trucks. The metal strip that is used gets worn out over time and needs to be replaced. You have 2 options:
1) You can just replace the sending unit that is located on the side of the fuel pump. Last I checked it was around $100-$150. Not sure what inflation has done to that since I looked.
2) You can replace your fuel pump for about $300-$350 or so.
Either way, you still have to pull the fuel pump out to fix the part. So, labor is going to cost you the same. Or, your time if you do it yourself. I had about 130k miles on mine, so I decided to go ahead and replace the fuel pump. To me, it just made sense to do all of it, since we were going to be in there anyway.
