From the description and the video it looks like the rear lift gearing has failed. To get access to it you need to remove the left side D-Pillar trim panel, that is the one all the way at the rear between the floor and ceiling. To remove it you remove the trim strips across the top and the bottom of the rear hatch, then remove the seat belt loop on short wheelbase and the bolt holding the seat belt on the long wheelbase vans. Then the panel pulls free of the clips. Disconnect the speaker if needed.
With that out of the way you will see the motor assembly on the pillar. Remove the wiring and then unbolt the lift assembly and lift it up and out. Now you can inspect the gearing and the levers to see where the failure is.
The motor number is 5019036AA and looks like the below image. The plastic piece is a common failure as it the internal gear.
Replacement of the motor is done by unbolting the motor from the lift assembly and bolting on the replacement. Then you install it and use a scan tool to erase any fault codes from the liftgate module.
Monday, May 31st, 2021 AT 2:25 PM