What is this wire harness for?

[Jenebo]

2017 GM Sierra 1500 Denali - Driver side, about by drivers door on inside of frame rail. It Y's off the harness that goes to some brake/ABS booster.

 

Was out hunting and found this hanging from under the truck after going through a field. Slid under but could not see anything to plug it into, so zip tied it up as the truck appeared to be running fine with no dash lights.

 

I got it back home and slid under it again with a light to see if I could find out where it goes, but again, cannot see anything. I slid under my buddies 2014 Silverado 1500, and his harness goes to something that has a fuel line running through it; I do not have that part on my truck. Anyone know what this is for?

Edited December 12, 2022 by Jenebo

[JimCost2014]

Think it is there from factory on all trucks, but is used if the truck is E-85 compatible.

[CamGTP]

Yep, every truck is wired for the flex fuel sensor but just about every truck built from 2016 on is not equipped with the sensor.

 

It makes putting a sensor into the fuel line pretty simple when people mod their vehicles.

[Jenebo]

That makes sense. Thank you for the replies.