Yukon XL Denali

Erratic Fuel Gauge Operation on GMC Yukon XL Denali

Problem Description and Possible Solution

It is common for the fuel level sensor in the fuel tank read the fuel level incorrectly. The sensor must be replaced to correct the condition. Our technicians recommend having the complete fuel pump module replaced on high mileage vehicles.

Problem Data
RepairPal Verified
Average mileage: 128,639 (10,300–210,462)
7 model years affected: 2001, 2002, 2003, 2004, more2005, 2007, 2009
45 people reported this problem
Viewing 1 - 20 of 21 comments
Fuel level reads then it doesn't. When it does it will read the correct amount then quits, back and forth.
Fuel gauge is showing empty then full. Will not display miles until empty. Occasionally starts working...
Fuel gauge was reading erratic. You could never tell how much fuel you had left. While removing the sender from the tank I noticed allot of corrosion in the sender's terminal housing. There was also one terminal with corrosion on it due to a failed o-ring which was causing the failure of the sending unit. GM has a kit which modifies the connectors, housing and o-rings which includes a new fuel level sender. Before attempting this repair yourself, make sure to get the fuel level in the tank as low as possible. Also while removing the tank, be extra carefull to remove ALL of the vent lines especially the smallest one which is about 4mm in diameter. It can break off very easily. They are located at the front end of the tank. Remove the rear fill hose and large vent hose in the back of the tank, then disconnect the brackets while supporting the tank, drop the back down and slide the tank backwards to expose room in the front of the tank to remove the small vent hoses.
Our fuel gauge would sometimes say we were on E when we had just filled up, or we would be on E one day and have 1/4 of a tank the next day. Our check engine light came on a week ago, we took it in and found out it's the fuel sensor. I was quoted around $500 to repair.
The weather temperature got to 99°F & the gas gauge went from quarter tank to full & kept jumping then stopped at half tank & hasnt been right since. Prior to that i had the fuel pump changed at 190000.
My 2004 GMC Yukon XL 1500 series truck's tank is full but the gauge is reading empty no matter how much gas is in there.
Just after i fill the tank and pull out, the low fuel light comes on and the fuel gauge drops. I just try to keep account of how many miles I am allowed on a tank and when the allowment gets low, I fill it back up.
I didn't have a problem with the sending unit until I pulled the fuel pump assembly to replace the actual pump and filters in the assembly, My fuel gauge was dead on accurate. when it said empty, it meant it. But after I pulled the assembly I was looking at the construction of the Rheostat ( where the little brass looking spring contact feet drag across the units grooved sensor board) and I saw a crack in that board. all the way across it. also the brass feet contacts were so thin the end look like Christmas tree tinsel! Not by design but by wear.
This design is made to fail is what I am gathering. I mean it's so cheaply made that the very slight pressure of those contact feet have literally less than a hairs breadth of wearing completely though. The hairline crack in, (the board there is comparable to an egg shell, maybe only slightly thicker.) The board is still reading across the crack with the Multi meter but i do not Think it will for long.

I didn't buy the whole unit as one piece because I wanted to keep what seemed to be a perfect working Unit and just replace the pump with a a high quality AC Delco part, But now I see I have a new problem. I need the part that goes on the side. the clipped on rheostat section with the contact feet. one that will read true and correctly display the fuel capacity.