Found a vacuum line hanging under my 07 h3 (auto trans) I suspect it may be a vent for the transmission or transfer case but I can't locate a port to plug it into. the line is on the driver's side and one end of it has a white filter of some type. Truck runs fine, no codes. Any ideas?

 

Transfer case and transmission breather lines.

Front Diff - terminates on the passenger side of the radiator
Tcase & Transmission - terminate where you see them / newer models have the transmission breather on the firewall behind the intake manifold.
Rear Diff - terminates near the rear of the fuel tank

 

Thanks Tainter, I found it