Shorting out?

[grovey]

I have a 02 Sierra 1500 Z71  that has a shorting out issue. The gas gauge has been wonky since i bought it. To begin with if you had like 1/8-1/4 tank and stopped hard the gauge would not come back up after bottoming to the E on the stop. The truck would have issues now and then on the start (in my driveway in park) with the wipers not turning off past the slowest intermittent  speed after clearing the windshield.

Twice the issue also included the truck's engine  missing,  gauges going haywire , and i had to pedal it to keep it running.  Shutting it down and restarting "solved" the problem.  The gas gauge will stop working and sometimes take 5-10 mins to slowly come back up. The problem was more likely when i filled the truck up, and as of late filling it up  led to the same gauges going nuts, sputtering, and it was making the trans slip in and out of gear unless pushing it to like 4-5k to keep it moving. Let off the gas, and the truck would free wheel like there wasn't a higher gear. 

I stopped putting much over 1/2 tank in it as a bandaid, but 2 days ago it started doing the tranny thing with just 1/4 tank which it's never done. Twice in a month it's done it in stop and go traffic on the interstate.  Turning it off , and restarting it has "solved" the problem all but a few tries.  I blamed the issue on a ground? on the gas gauge float, but that doesn't explain it taking a fit while parked in the driveway.  Sorry to write a book, but it has alot of symptoms.  Anybody had to deal with something like this? 

Edited September 11, 2021 by grovey

[Sharpz]

never had to deal with all of this, but my 99 did have the gas gauge issue.  I ended up changing the pump and it all went away.  I was told at the time it was a sign the pump was going bad.  I honestly cant understand how that would have a problem with your truck running good, or your tranny having an issue.  To me that sounds like a ECM issue, especially since if you shut it off and restart it seems to correct the issue.

Edited September 11, 2021 by Sharpz

[dna9656]

I agree with Sharps, but I think you have more than one bad ground. I would check the connections of the fuel tank float circuit from tank to gauge, and while you have the tank down and the tank is hopefully closer to empty rather than full change the float/pump assembly. That's where the fuel filter is as well (usually these days) and it prolly could use a new one, it certainly wouldn't hurt anything but your wallet. Try Amazon, Rock Auto, or Parts Geek.

The PCM may have poor connections/bad ground(s) and also if you have a computer controlled transmission you could be suffering from poor connections/bad grounds) there as well.

Good Luck!

[grovey]

Thank you for the replies.  I should of replaced the pump and cage long ago because of how it acts up. A buddy had a good used setup from a truck he parted, and the plan was to try that cage and a new pump, but i'm pretty sure that's been tossed now. When the tranny acts up the gauges are going haywire as well. The truck has never not started up, and the tranny has never acted up  without the gauges going haywire at the same time, but only once can i remember it running rough during the tranny acting up. It has never acted up past like 30-35 mph.   Sometimes when the gas gauge acts up it drops to E and a few seconds later it pops back up to full( after a fill up) Sometimes it'll take 5-10 mins to sloowly creep it's way back to the correct reading.