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.Google+
Car Problem Reports
GMC Yukon XL Denali Fuel Level Sensor Failure
GMC Yukon XL Denali Problem
Average Mileage: 127,317 mi (65,000 mi - 210,462 mi)
Visitor, 2002 GMC Yukon XL Denali, 78,600 mi
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.
Visitor, 2003 GMC Yukon XL Denali, 190,000 mi
Fuel level reads then it doesn't. When it does it will read the correct amount then quits, back and forth.
Visitor, 2004 GMC Yukon XL Denali, 132,000 mi
Gas gauge stopped working.
Visitor, 2001 GMC Yukon XL Denali, 112,000 mi
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.
Visitor, 2001 GMC Yukon XL Denali, 210,462 mi
Fuel Gage works well, then suddenly goes to empty, then back up...
Visitor, 2001 GMC Yukon XL Denali, 200,000 mi
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.
Visitor, 2004 GMC Yukon XL Denali, 65,000 mi
gas gage sticks in place and will not move
Visitor, 2004 GMC Yukon XL Denali, 91,250 mi
fuel gauge is reading way below empty but the computer states the correct fuel level though.