2005 Yukon XL Gas gauge problems

[iam4uf]

Hi, I have a 2005 Yukon XL 5.3 liter. I replaced the fuel pump two months ago due to a pressure issue (having to start twice to get it to start). Everything went fine with the installation and for the last two months all worked fine.

My Wife filled her tank up 3 days ago and the gas gauge went well beyond full (See Pic). The computer range works fine. After a couple of days it looks like the gauge goes down but when its empty it shows half a tank (see picture).

Anyone have any idea what the problem is. I disconnected the battery hoping it might reset but that didn't work. I don't think its the sending unit since the computer (miles til empty) is working.

http://i848.photobucket.com/albums/ab45/iam4uf_2009/614f725c-4ef7-4d56-89ae-f7392c6dd993_zpst0fzctot.jpg

http://i848.photobucket.com/albums/ab45/iam4uf_2009/IMG_22711_zps00yrc7sz.jpg

[Doug_Scott]

The miles to empty does not use the fuel gauge, it uses the pcm to interpret fuel flow numbers. By looking at duty cycles of the injectors, and a predefined table of flow numbers it can calculate fuel usage. Not sure how it knows when the tank has been refilled though. It may use the gauge reading(not looking at what the gauge is showing, but taking the impedance number from the in tank unit).

 

You may want to take it back to the shop that replaced the tank unit and have them verify all the connections are good on the tank unit. It should still be under some warranty I would think.

 

Years ago when ethanol first started showing up in one particular brand of fuel (PetroCan), GM up here had a issue with fuel tank sending units acting up like you have described. GM was good about changing the sending unit under warranty, and about 8 months later I got a PetroCan gas card with $60 on it. It came with a letter saying this was just to compensate for the inconvenience of having the tank unit not working properly, and was very clear in saying this was not them admitting fault for the failure. From what I could tell it was only PetroCan that had this issue, how could it not be there fault?

[iam4uf]

So we drive the Yukon until it got to 1/4 tank and the gauge started working. We filled it up again and all seems fine. Guess I will see if it happens again.. very weird.

[Doug_Scott]

So we drive the Yukon until it got to 1/4 tank and the gauge started working. We filled it up again and all seems fine. Guess I will see if it happens again.. very weird.

 

If you feel adventurous you may want to try refueling at that station again and see if you have the issue again. Any chance you happen to know anyone else that uses that station to see if they had any odd experience?