2002 Chevrolet Suburban should hold 31 gals. with gauge on E and low fuel light on pump topped at 19 gals and gauge reads F?
Fuel gauge float arm in tank may not be going down all the way.
Error in the sender or gauge is reading incorrectly, the only way to know for sure is to have the system ohms checked to see if the gauge responds to the correct ohm reading for the set amount of ohms for a full, 3/4, 1/2, 1/4 and empty, if it reads properly then the sender has to be checked to see if it is sending the proper set of ohms for each fuel level, if everything checks as it should then you either have a damaged fuel tank or rare as it may seem you don't have a 31 gallon fuel tank.
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