[Pierre26]

@ramez75, First see the Ref of each module to know what exactly they are. My PDC is ONE module (for front and rear) with 3 plugs and located in the center of the plastic basket and I putted the PassiveGo in the outside housing one to be side by side to be able to do the connections on the X300 about the 2 Kcan wires. The trailer module is half width / the 2 others.
According ISTA PassiveGo is A215, PDC is A81a and Trailer on is A6, see page 13 and 14 of the doc, pics are shown about these.
According your last pic you gave PDC have the same place as mine (center), just add the Passive Go outside.