Tire pressure monitoring system: Car manufacturers rely on two different technologies. Tire pressure monitoring systems have been required by law in new vehicles since the end of 2014.
In older vehicles, however, the TPMS can often still be missing. There are various retrofitting options for passive and active systems. Solutions are often offered for low to medium double-digit euro amounts that consist of four tire valve sensors and a display, which can be connected to each other via Bluetooth, for example. You save costs by using the ABS's existing wheel speed sensors to check tire pressure.