How do I check the IAC control solenoid on a 2002 Xterra throwing code P0505

Question

Its not idling ruff or running bad someone els just replaced fuel regulator and messed with the throttle body trying to adjust the idol and theres a little vacuum tube with no hose on it coming from under the upper intake mannafold. I can not see where the vacuum hose would go if it was there. Help registration is due and cant pass smog

Answer 1

P0505 ISC system

with that vacuum hose being disconnected that just could be it. It would also help to know if there is a another code to see where it went to such as a EVAP code, then this would lead you to the EVAP purge hose. other than that if there is a underhood vaccum diagram that would be better