The Adventures of Sylvester, the 2018 Suburban 3500 HD

[Bigburb3500]

Huh. Wonder if the 1500 Suburbans have a flaky gas gauge from time to time or if it’s something unique to the 3500. We stopped at a rest area while the gauge wasn’t working, and I shut it off and restarted it but it didn’t fix it. What fixed it was stopping for gas and leaving it shut off for 15 minutes while we got some food in the store afterwards. Fired it back up and the gauge wasn’t back to normal and hasn’t flaked since.

I think mine was out for a full day or it came back while driving… can’t remember but same thing. Happened once, several cycle on-off and no change but then came back and no issue. Odd issue

 

[Fless]

I may be hallucinating but do these have dual tanks? I thought I recently read about a second fuel level sensor in the second tank that could affect this.

 

[Geotrash]

I may be hallucinating but do these have dual tanks? I thought I recently read about a second fuel level sensor in the second tank that could affect this.

They do indeed have dual tanks - pretty much the same setup as the GMT900 2500 SUVs. I had a similar thought but since it only happened once, I haven't been too motivated to try to figure it out. That said, I will put some time into it anyway - if for no other reason than to figure out a reliable workaround when I experience it.