Dave,
Actually what would happen if you lost a sensor is you would get a no sensor display.
When you start the programming, in the program mode and you lock on the wheel you want to program, you get a no sen er indication on the monitor. You have 10 minutes to screw on a sensor. When the sensor transmits to the control panel once installed, it sends the base pressure. Once this is established it's looking for a 12 % drop for an alarm but will still continue to send the current pressure it sees.
If the sensor is lost, there is nothing to communicate with the control panel.

Big Bad John & Runaround Sue & Paris