Right ok, Looks like they are modified units . . .
Not sure how the load level motors are adjusted. . . probably via the dial on the dash.
They have been fitted with LED bulbs so they will probably have ballast resistors on the bulb power lines to fool the BCM and bulb check.
I've not seen these fitted yet, and dont know anyone with them . . . . . . so lets see if anyone else pops up with any comments.?
Sounds like the BCM (ECU) in the van is detecting a bulb fault even though you have that LED kit fitted (ballast resistors?) . . . . . It might be something you have to ask the seller about.
Maybe the new loom has different value ballast resistors? . . . . have you got a detailed pic of the loom at all?
I did notice a comment from some generic information about fitting aftermarket LED bulbs in standard headlight units
This listing is for a set of LED bulbs + a pair of canbus free error resistors only
Canbus systems can be temperamental with upgraded LED bulbs even when fitted with resistors, there is no 100% guarantee they will work on all vehicles
Load resistors get very hot, just like bulbs. So please make sure when mounting you do not mount on body/paint work.
and
Please note: The philips led bulbs are for off road use only however they will pass an mot because they go through the projector lens and create a perfect beam pattern.