Def level

[Bwoody]

Have 2015 lml and put 4 gallons of def in a week or so ago. Today I noticed level was 30%. So went out and added a little bit more. Drove vehicle for 8 hours and went down to 29%. Do I have bad sensor some where? Temp had been below 20 for quite a while. Tank maybe frozen

 

[NC-smokinlmm]

Are you pulling heavy? I've been told cold weather driving will use more def also. If not you may have something going on, I get about 6k out of a tank and I pull a decent amount weekly.

 

[DangerousDuramax]

This is a common problem that GM is aware of. Its a flaw in the software for the DEF but can't be corrected without completely rewriting the software. Head to you dealer and let them readjust it.