sensors are coded per wheel, not per location.
if u rotate the wheels, the order will change on your screen.
for example, if u damage a rear-left sensor, u cannot replace it with any other one, except a new rear-left sensor.
best way to know which sensor is which, deflate and reinflate one at a time.
i deflate and inflate my tyres minimum once a week for offroading, and i love the TPMS!
EDIT - the sensor is proximity read, so when the tyre is off the car, the screen will show stars **** until the tyre is close enough to be read. it takes between 5-7 seconds for the screen to update