Chrysler Repair: 2004 Pacifica Fuel Gauge, fuel gauge, fuel level

Question
We have a 2004 Pacifica that the fuel gauge jumps from full to low fuel makes the "ding" and then jumps back to full.  It can be at a full take or even lower and still it jumps from empty to full and keeps dinging.  It has been exceptionally cold, here.  We added a can of "heet" thinking the line might have some water in it but this morning it was jumping like crazy.  Could this be an expensive repair?

Answer
I've done two pacificas with this problem and both times it was the fuel level sending unit sensors and theres two of them inside the fuel tank and I recommended replacing both while I had the tank out of the pacifica Thats what it sounds like. You can try having the fuel gauge recalibrated first if you would like at the dealership but I tried that on both pacificas with this issue and they both came back days later I hope this helps