Jumper Harness and Communication
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
There is a jumper harness between roof opening panel C921 and both roof opening panel assembly motors (shield and front sliding glass panel motors) which includes a communication circuit that is used only for communication between the motors. If the communication circuit between the front sliding glass panel motor and shield motor is open or shorted the front sliding glass panel motor will only fully close the front sliding glass panel one time, then not operate. Also, if the communication circuit is open or shorted the shield motor will open fully, then only operate between fully open and the front of the fixed glass panel.