Finding engine ECM part number?

My "Service Engine Soon" light came on and a code scanner yielded P0443 which I have researched and found could mean I need to have the engine ECM reprogrammed or need to replace a evap cannister vent control valve. I have found plenty of info on the latter but in order to know if I might just need to have the ECM reprogrammed the TSB that I paid $12 for says that a "C-III" should be connected to the vehicle and the engine ECM part number determined (by reading it off the ECM Reprogramming screen of the C-III) to see if it is one of the ones listed in a provided in a table that require reprogramming. I have no idea what a "C-III" is but I suspect it might be something that only a dealer has. Is there any way of establishing the part number of my engine ECM other than this? Is it printed on the engine ECM? And, where might the ECM be located? Also, does anyone know if this would be covered under any warranty or recall - my Xterra is a 2008 w/ 50K miles. Thanks

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.

Thanks, I found the ECM but the only identifying info on the case was a sticker with the manufacturers name (Hitachi Automotive Products) and a bar code with no numbers underneath it to tell me what the bar code might read but with the following letters and numbers: MEC71-020 C1 7Y01A. Any other thoughts on how I might find the part number?