There are two types of tyre pressure monitoring systems, direct and indirect.
Direct - each wheel has a sensor that measures pressure and transmits this to the car. Lexus models differ in how this is displayed. Some display individual pressures for each wheel. Others only have a warning lamp that illuminates should one or more tyres dip below a threshold pressure. This can be a very sensitive system, generally alerting at ~10% deviation
Indirect - the car uses the ABS sensors to monitor wheel revolutions, should one or more wheels show a significant increase in rpm the system assumes one or more tyres are deflating, thereby reducing the rolling circumference. The system will illuminate a warning lamp. A crude system alerting at ~25% deviation
As posted above all cars after 2012 must have some form of TPMS