Gas Gauge Issue

[Gun Runner]

I have a 2018 LT Suburban and the gas gauge is kind of going crazy. When I fill up the gauge registers a full tank just fine but when I shut the vehicle off and turn it back on, it only registers around half a tank. I know I didn't burn a half a tank of gas because the most recent time I only had 10 miles on the tank. The gauge will slowly creep up to about 3/4's full during a drive but never go to a full tank. This has happened on the last two fill-ups. I searched and couldn't find anyone with similar occurrences. Any ideas what the problem could be? Fuel sending unit or float in the tank?

 

[Big Mama]

I think this is a known issue. Look up TSB on your rig I may be thinking of an earlier model. Yours is under warranty, no?

 

[Gun Runner]

Thanks, I’ll look up TSB’s later tonight. And yes it’s under warranty but I was just thinking if it’s something I could rectify I would. I hate having to take a vehicle in for warranty but I obviously will if I have to. Thanks again

 

[zbad55]

Yes take it back to the dealer, sounds like a fuel sender module issue.

 

[renotahoe]

This has just started on my LT Tahoe. Did you take it in and if so what did they do to fix it?

Thanks

 

[Zwilly001]

This is going to sound ridiculous, but hear me out. I had something similar. Took it to the dealer to have them check the sending unit, which was fine.
Kept an eye on it and realized that it happened every time I filled up at the Mobil gas station, but never at the other stations I normally use. Tested a couple of times since by filling up at Mobil and it still happens.
There is no reason why this should happen that I can think of, but who knows.
Try going to different stations and see if it happens every time ?

 

[Boatguy]

My 2017 Yukon Denali quit registering full. It moves around between 5/8 and 7/8 full. Haven’t taken it in yet. Still under warranty.