I installed the hitch myself from etrailers, also got the wiring harness from them. Both were an easy install and they have videos online. I didn't know our trucks had any software that detected a trailer being towed. Are you referring to a brake controller?
'12 ML350 BlueTec Black/black, P2, lane tracking, trailer hitch, wood/leather wheel, Zaino, Amsoil 5w-40
'11 Honda Accord EX Basque Red Pearl, Zaino, Amsoil 0w-20, 4cyl, 5spd manual
'08 Toyota Rav4 Black w/ ash int, 4wd, Zaino, Amsoil 0w-20
Retired: '10 MDX Tech, '08 Honda Accord LX, '06 Nissan Xterra S 4wd 6spd manual, '00 Nissan Xterra X 5spd manual, '98 BMW 528i, '95 Mazda Millenia