2004 XC90 Cooling Fan Inoperative

[mhcoleman]

Hello Folks,
My daughter's 2004 XC90 electric cooling fan appears to have failed. I checked the wiring and it has 12V at the red wire on the big plug, as well as ground on the black wire. The trigger wire has me confused, does it carry power or a ground signal? The car's temperature gauge is also inoperative. I changed the temp sensor on the head and that has not changed anything either. I also replaced the cooling fan with a new one, again no change. Am I looking at a rebuilt ECM?
Best Regards
Mike Coleman
Ontario, Canada