Were you able to make any progress with that chart? I have the same system on my 2014 Caravan. When looking at the computer data, I don't have any listings for position sensor voltages like those you found. The two position sensors are shown, but with "number of clicks".
The one I helped my friend with was on a Caravan rebuilder a few years ago. It did exactly as what you described, but we found it was the transmission range sensor that was out of adjustment. It still performed the neutral safety switch function correctly and the starter system worked, but the Liftgate Computer was seeing it was not in "park".
I'm adding the diagram for this system below, if that will help. The two position sensor circuits are shown at the right side of the third diagram.
Please keep me updated on your progress.
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Wednesday, May 3rd, 2023 AT 4:18 PM