This is the Fast Idle or Idle Air Control Valve. Depending on the setup it does act as the choke by sensing the coolant termperature. That is why it is part of the coolant circuit.
Some vechicels have the Fast Idle, (which is more like a choke) and the Idle Air Control, (which open the throttle more as load increases), as a unit or seperate parts. I cannot recall of hand on the Pathfinder. I think they are seperate. Make sure you get the right one because the Idle Air Control Valve is mcuh more expensive.
Purchasning a Haynes Manual or the online Mithcell1 manual offered through this sight will help identify the part.
Let me know if you have any other questions and I wilkl keep any eye on this post.
Monday, November 22nd, 2010 AT 9:10 PM