Need help locating where this wire goes

[Illfish01]

I have a 2018 6.7 Cummins diesel, was doing some work on it and found this wire and have no idea where it go, it is on the drivers side behind the cp3, it is on and branch of the wiring harness with to other plugs on it, one of them going to the egr, can someone please help with this

 

[18CrewDually]

The black portion on that is a protective cap. That plug is not used and left for diag. I will verify later and post back on my '18.

 

[18CrewDually]

It should just be taped to the harness. Here's mine.