The pump does two things, produce vacuum and produce pressure.
1) it produces pressure to unlock, and sends this pressure to all the door, fuel lid, and trunk lock, thru the yellow line ZV. It also shuts down if it does not get a lock signal back in 10 second.
2) It sends pressure and vacuum to the backup rods thru the orange line RH
3) IT sends pressure and vacuum to the trunk lid handle thru the black line SFG
4)It produces constant pressure for the orthopedic back restthru the gray line P+
5) It provides back up vacuum for the HVAC, when the engine does not provide ample vacuum thrut ransparent line P-
you have to figure out what it is doing
If it runs intermittent it is either trying to replenish the pressure reservoir for the lumbars or the vacuum rervoir. I suspect you have a leak somewhere, go to your local auto parts supplier and get a "mighty vac" tool. It is designed to draw a vacuum and has a guage so you can see if you have a leak down. You can plug it into the hoses and see if they hold.
I dont know what would cause it to run while the car is in gear, unless it is trying to retract the back up assist rods?