The radio, navigation, and cd player, etc are not working on my xc90. I read that it was best to jiggle some wires. I went to jiggle the wires under the passenger seat and the big red wire wasn't even connected. Decided to inspect this big black box by pulling it out and saw a BUNCH of corrosion.

What is the full name of this box? Not just the abbreviation. Part number?

If I find a used one on ebay is there anything I should be worried about as far as compatibility?

Will I need to taker the car to the dealer for a software upgrade?

I did see red light coming from one of the cables I unplugged. I'm hoping this means the ICM is good or is this just wishful thinking?

If I decide to buy an aftermarket stereo will I need to buy a black box anyway? I really don't care if I lose the navigation or cd changer

I realize some of these questions have been answered but I was having trouble relocating the information after I first started researching last week so I do apologize if some of this has been covered