Help Identifying Vacuum/Vent Line on 2011 Rear End

[HookEm]

Anyone know what this line is for and where it’s supposed to terminate? It looks like either a vacuum or vent line but I can’t locate where it came from. No lights or warnings have shown up so far.

 

[B E N]

Axle vent line. Look directly above it at the bed cross support, there is a nipple for it to attach to.

 

[MTF]

This is the vent hose, so somewhere up on the frame or bed frame is the plastic nipple that the hose fell off.

 

[HookEm]

Thanks for the feedback. Much appreciated.