Just to update this a bit more about a possible flash being needed. I opened the tow wiring kit and it includes a body control module that is added along with the harness. I am pretty sure it will need a flash to make it work but maybe not?
Another note. It appears from the directions( which SUCK - just bad drawings - no text at all - typical MOPAR )that there is actually no under the hood( i.e. engine compartment )hook up which is good as those are a pain. HOWEVER, you have to take out the spare tire and spare tire well trim, the driver's side cargo area trim, and then strip most every piece of lower level interior trim out that goes down the driver's side of the vehicle up to the dash where you get to pull the lower dash trim. The harness goes down the driver's side to the dash where it goes in behind the dash to a fuse block there. A big ass hole has to be drilled in the rear for the harness to go out too.
Looks like the harness install is not for anyone but an experienced DIY'er or you could easily break interior trim panels. I did a similar one to this a few years ago and I will never do it again. I know what I am doing but gutting interiors just sucks plain and simple. I am having either the dealer or my body guy do it. Planned to anyway but after seeing the directions there is no doubt about it.