Question

I have a 2004 Ford Explorer with engine code P0506, where is the IAC located?

Answer 1

P0506 Intake air system

The IAC is part of the throttle body.If you are getting a hard start or idle fluctuation , clean the throttle body passage, Hopefully this will help, But you have to disconnect the battery, clean out the throttle body, There is also a TSB 12-7-4

Answer 2

The code means that the engine Idle Speed is too low. Start by cleaning to throttle body

P0506 FORD Code - Idle Speed Control System RPM Lower Than Expected
Read more: https://www.autocodes.com/p0506_ford.html