Help, please. Is the 3 Way Coolant Valve covered under the extended warranty?

I drive a 2006 Prius. Yesterday (Saturday) while driving the freeway, the check engine light came on so I drove right to the Toyota dealer. The service rep told me that to scan it on a Saturday would be $150. If I wait till Monday, and it's covered by warranty, it will be at no cost. I made an appointment for Monday and took the car to Auto Zone, where they scanned it and came up with code P1121, which according to a post here, is most likely the 3 way coolant valve. I searched and can't seem to find out if this part is under the extended warranty. Should I tell the service rep that I had it scanned at Auto Zone? Any help would be much appreciated. I don't want to be taken advantage of when I go in tomorrow. Thank you!

 

I can answer my own question, in case anyone else has the same question. It was covered under the extended warranty.