Air Inlet Selection
WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
When fresh air or RECIRC mode is selected, the FCIM sends the desired selection to the HVAC module using the message path described above. The HVAC module drives the air inlet mode door actuator until the HVAC module detects the actuator reached its end of travel. A spike in current draw tells the HVAC module the actuator has reached the end of its travel.