C-III (CONSULT 3)is the Nissan scan tool we use for diagnosis.
The ECM is located in the engine compartment , the far back corner on the passenger side , there is a black cover over the connectors, the part number is on the case). It will begin with 23710-xxxxx.
There is a TSB ( Technical Service Bulletin) for this issue , it refers to bugs and or debris getting into the vent control valve causing it to hang up.
Be advised a TSB is NOT a recall, it is information sent to the technicians for diagnosis purposes from the manufacturer.
The fix is to install a new vent control valve and a inlet air filter kit to prevent this from happening in the future.
I'd read your warranty information manual to see about coverage or call the dealership.