I have a technical question for anybody that can answer it. I have a brand new 2016 model P3P. . When I listen to my ultrasonic sensors I can hear a slight clicking. The problem I'm having is when I cover one of the sensors (with my finger), only one of them is clicking and the other does nothing. Is it because one is for transmitting and one is for receiving? If somebody else can try this out please let me know what you find I would greatly appreciate it.