All vehicles these days are required to have a tire pressure monitoring system (thank you, Ford Exploder)...
They basically fall in to two camps:
There is the cheap and limited version that simply uses the ABS wheel speed sensors to compare the rotational speed of the four tires. When a tire drops pressure, it's speed will increase and this can be used to detect a low tire. The main problem with this system is that it won't detect if all tires are equally low. It can also be fooled if you put new tires on only one axle.
The much better but more expensive system actually uses tire pressure sensors in each tire to wirelessly send the actual tire pressure to a monitor in the car.
Does anyone know which version the Leaf uses? Based on the fact that I did not see a tire pressure readout anywhere in the data screens for the instrumentation in the car, I'm forced to conclude that they took the cheap route...
Leaf SL 2011 to 2016, Volt Premier 2016 to 2019, and now:
2019 Model 3; LR, RWD, FSD, 19" Sport Wheels, silver/black; built 3/17/19, delivered 3/29/19.