2016 Equus Parking assist system control module

[Hund2016]

Having issues with my rear parking sensors, issue comes and goes but it shows a bar across all of the rear of the car when it goes out and does not identify any specific sensor is having a problem? When it is working all of the sensors individually work when I walk behind the car. So I am suspicious of the actual control module that runs all of them? If I replace it does it then have to be calibrated at the dealer, or is it plug and play, system will just reboot and work? Also some of the diagrams say it is in the front of the interior cabin between driver and passenger, manual says it is in the rear passenger side of the trunk? and the manual seems to say there are two of them while only showing one? With two arrows pointing to the same thing? Any help would be appreciated.