2013 Toyota Yaris - Fuel gauge

When I am driving my car the gauge stays in full. When I turn it off it returns to the bottom level. How to fix this

How to fix it depends on what is wrong… fuel sender, wiring or gauge.

My 2009 Corolla does the same thing. As far as I know the fuel gauge doesn’t work when the ignition is off and it returns to E. Is the gauge accurate when the ignition is on? Does it indicate Full all the time? If the gauge is working there’s nothing wrong.

Take a rubber mallet and bang on the bottom of the gas tank to see if the gauge starts working.

Tester

Did you not read the post ? Key off the gauge goes to Empty - key on and engine running and car moving as he is driving the gauge reads full all the time.

The OP said “When I am driving my car the gauge stays in full.” I took that to mean it goes up to full when he starts the car with a full tank, not necessarily that it stays there all the time. I could easily be wrong but until I have more information I’m not convinced there’s a problem.