DEF fuel gauge stuck on full 3.0 L

[2024 3.0 Duramax]

My 2024 Duramax 3.0L DEF dash fuel gauge seems stuck on full, with about 15k on truck still under warranty. I noticed it had not moved after about 2.5k miles since last refill, where it’s normally down 1/4 - 1/3. I try to refill when it’s down to a quarter full on the dash gauge with fresh DEF. It’s well above freezing, and using approved DEF, cap on tight. Any ideas? Thanks

Edited December 30, 2024 by 2024 3.0 Duramax

[Jus Cruisin]

My idea is to contact your dealer and get it diagnosed. 

[redwngr]

Or ignore it and drive on.

 

 

[Z45]

Mine is only down 2 bars at 3,000 miles and just recently showed that. Was only 1 bar around 2,500. 

Edited December 31, 2024 by Z45

[2024 3.0 Duramax]

Thank you for the replies. All are note worthy. 

[Paul Hurtt]

My 21 Sierra has the opposite problem. The DEF indicator goes to empty intermittently. I get the empty warning, with the speed reduction in “X”  number of miles. Service bulletin for DEF software flash done by dealer. Went to empty again after a week. Dealer changed DEF tank. Happened again a month later. GM in Detroit says likely bad DEF tank. I’m awaiting another DEF tank, along with a full day without my truck…