2002 Suburban 2500 4x4 Fuel Gauge Issue

Vwracin2win · February 9, 2020

Hey guys new here. I have a 2002 suburban 2500 4x4 6.0 with 240k on it. I love this thing and it runs like a champ. But about a month ago I was moving my travel trailer around the back yard and my kids were in playing with the knobs and buttons of course while I’m hooking up and unhooking I go back inside to move it and the fuel gauge was dropped to E and the light on I was suspicious because I drove it to work the night before and put some gas in it. I didn’t fill it but I knew it had gas in it. You turn the key on and the fuel gauge will jump to the level of fuel the tank has then immediately fall to E and then the light on. I was like well it probably needs a sending unit so I dropped the tank and replaced the pump and sending unit. Go to then the key on and it does the exact same thing, gauge jumps to the correct fuel level then falls to E with the light on. I figured there was only one other thing it could be is the gauge itself being the clusters are known to have issues. Sent out the cluster to get it rebuilt entirely and put it in tonight, exact same thing turn the key on, gauge jumps to correct level then falls to E and turns the light on. I have no idea where to go from here. It doesn’t seem like a frayed wire issue or anything because it does the same thing every single time you turn the key.

does anyone have any advice? Thank you.

Colossus · February 9, 2020

The fuel level sensor in the gas tank is VERY prone to failure in the GMT-800s. most of us who owned one ended up replacing the modules (entire modules, including the fuel pump AND sensor) and it's probably time for yours to be replaced too. Though most of ours were replaced before 100,000 miles

Vwracin2win · February 9, 2020

2 hours ago, Colossus said:

The fuel level sensor in the gas tank is VERY prone to failure in the GMT-800s. most of us who owned one ended up replacing the modules (entire modules, including the fuel pump AND sensor) and it's probably time for yours to be replaced too. Though most of ours were replaced before 100,000 miles

I just replaced the entire unit though. Everything is new in the tank.

vucelick · February 9, 2020

my new sending unit went bad about 2 weeks after installing it, same symptoms as yours.

tigers2007 · February 24, 2020

Remember that your GMT800 Suburban 2500 has two fuel tanks and two senders. Do you have access to a Tech 2?

carkhz316 · February 24, 2020

If it's just a sending unit issue, both Dorman and S.U.R.R. make a repair kit for the sending unit and the contacts (the part that wears out and causes issue 99% of the time) in most GM vehicles from the 90's-00's. They're both around $30-40, but involve removal of the fuel pump and sending unit assembly anyway. But, at 1/10th the cost, it's a much more cost effective alternative.

Vwracin2win · March 14, 2020

Alright guys, thank you all for your advice and feedback. I finally figured it out!

my suburban did in fact have another gas tank above the spare tire so I replaced that fuel pump and sending unit assembly with another Delphi unit and it works. Hard starts went away as well.
I hope this helps. Atleast I know both pump assemblies are new and the gauge cluster is all good to go.
thanks again guys.