Where is the control solenoid located?

I'm replacing the control solenoid of a 2001 ford taurus but need to know where it is located

Which one.

Uh, no such thing as a "control solenoid" but your Taurus does have many solenoids that control a wide variety of things from shifting or secondary air injection to gas canister purging. Yes there are literally a dozen or more. What 'chew tryin' to fix there Gomer?