the sense line checks out good... how was this checked? also, stupid question but battery is ok?

definiantly you do not have a hydraulic problem, rather a control problem on the contactor panel. nothing devious about this code. the book is absolutely correct for 40 series codes not like 50 series codes where it could be an array of components not listed.
the fact that you say the pump runs for a few seconds is telling me the contactor is functioning as it should and all fuses are good.

please ohm from TP3 (anywhere on lift motor fuse) to jps14-7 you should have contiuity, if not place P sense line after lift motor fuse. if you do your screwed... jk. tractor manager / vfc. but u did already so i think the wiring is bad.
did you conduct test a08?
truck operates fine other than this?