July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!
Module Network Input Messages - PCM
WARNING: This page is about a different car, the 2014 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
Broadcast Message
Originating Module
Message Purpose
A/C request (gateway)
HVAC
module
This message requests the A/C compressor clutch to be engaged.