2015 Hyundai Sonata SE: Incorrect Gas Reading

The car's at the age where little things plague you. In this case, I'd look to a defective fuel level sending unit; that's what communicates the fuel level to the gas gauge. Or a fault in electrical power going to the sender. The fuel pump has to come out. If you don't mind spending a little more on this, you could just replace the whole fuel pump. It comes with module & sender, strainer, float, and sometimes the filter. It makes the job easier and then you have new pump.

Hi, Try this first ! This has happened to me on a few different vehicles. Even different makes. The solution was shared to me by a mechanic. Electronic fuel gauges use resistance as the method of measure. The contact points can get a film or become dirty inside the tank. My friend said that it's from cheaper gas a with high ethanol percentage, you can use a bottle of *Techron from you local auto parts store. Some times it takes 2. sounds odd right? Consider this: For me it happened first in 2006 when gas $ was very high. Now it happened again same thing, (2022) adding 10$ or 20$ not filling all the way with this high ethanol that was added to help the supply issues. The ethonol can be higher in the winter and from different sations. Now my vehicle is parked due to less driving. The gauge is always right around the same place. It's sticks. I had a quarter tank at a stop sing and the gauge began to drop, to empty My car died. That never happened before.. It's not that old. The modern gas pups and gauges are inside the tank and very expensive to work on. Kindly note that the gas inside cools the gas pump and it can overheat if your driving on a low talk all of the time. This is understandable because it's so expensive at some stations and we pass them. Modern gas pups and gauges were designed to not fail. They also were tested under, some what normal conditions. It is high ethonal that cuses the sticking, I have just been keeping my tank full as I can..... I hope this helps even 1 person :)