I have a 2006 Gmc sierra 1500 WT, and for some odd reason the gas gauge is a little off. Now the gas gauge works and reads fine, but as soon as the needle makes it way to the 1/4th line, it completely stops and i cant tell how much gas i have left. Sometimes it runs for a good while after that needle stops on the 1/4th, other times as soon as it get to the 1/4 thats it all the gas is gone. I’ve gotten use to it just filling the tank every now and then but im trynna figure out the problem
I would imagine a problem with the fuel sending unit, GM has had problems with that on some model years, but I do not recall which ones, early 2000 to mid 2005 I think.
Some GM gas gauge problems are due to sulfur deposit build-up on the sending unit.
Try adding a bottle Techron Concentrate Plus to the gas tank at the next fill-up.
It may take more than one application to be effective.
@Tester beat me to it! A bottle of Techron should help a lot. Use it first anytime the fuel gas reads funny.
You might also check a pair of ground screws just below the driver’s left foot on the frame under the truck. There should be 2 black wires secured by 2 screws into the frame. Unscrew the grounds and clean the corrosion of both and reconnect. You can put them both under one screw if you like. A dirty ground in that spot can give your dash display funny readings, too.
My guess is a stepper motor failure, cheap and easy fix if you can do a little soldering. I got the kit because a number of gauges were whacko, oil pressure and tach speedo and maybe a couple of others, he $22 kit came with new bulbs, I did not do at the time, wish I had. Not recommending this but just showing you what may be out there.
I actually had a similar problem on my mom’s old car
At around the 3/4 mark, the needle would instantly drop to 0. Anything above or below 3/4, and it was fine
The cause was dirty contacts on the sending unit(s) . . . the car happens to have a saddle tank with two sending units
Anyways, I started filling up at Costco, which has top tier fuel, and the problem went away
that was quite awhile ago, and the problem has not reoccurred
So it might be worth it to start using top tier, if you’re not already. you might get lucky
If that gauge uses GM’s actuator motor movement, a problem with the actuator would be my first guess. All the other ideas above are possibilities too of course. It may be possible to disconnect the sender and install a test fixture sender that you dial yourself to see if the dash gauge responds to what you dial in on the test fixture or not. That way you could narrow in where the problem lies.
More likely the sender itself
Often, when the stepper motors fail, they fail at one end or the other
Always reads empty
Always reads full
I’ve also seen a few bad stepper motors that actually make some annoying noise behind the gauge’s needle
Yup. There was even a class action lawsuit on the issue.
I too am going with a sender problem. Whether it’ll turn out to be sulpher related would require removal of the unit, which will probably end up being necessary anyway.