Vehicle safety with TPMS
According to EU Directive 661/2009, it is a requirement that vehicles that have received type approval since November 2012 and new vehicles sold after November 2014 must be equipped with a TPMS (Tire Pressure Monitoring System). In Finland, Trafi has stipulated that this system must be active at the time of sale, with sensors installed in the vehicle's original tires, i.e. the tires with which the car was first registered. Although subsequent tires do not necessarily have to have sensors installed and it is possible to turn off the system, it is strongly recommended to use the TPMS system. It monitors tire pressure and helps reduce emissions, costs while promoting safety.
Functions and Mechanisms of Action of TPMS
The TPMS system works by monitoring tire pressure using either active or passive methods. In an active system, the sensor directly measures the tire pressure and temperature in each tire. On the other hand, a passive system only detects a decrease in tire pressure by observing changes in the tire's rolling speed. Both systems alert the driver by illuminating the TPMS indicator light on the dashboard when the tire pressure drops to 25 % below the recommended tire pressure.
Relearning and Identification of TPMS sensors
In order for the vehicle to recognize new sensors and extinguish the TPMS indicator light, a reconfiguration must be performed. There are three main methods for this:
- Auto learning: The vehicle will automatically detect the new tire pressure sensors by driving until the TPMS light goes out.
- OBD (On-Board Diagnostics): The new sensors' individual ID codes are configured in the vehicle's central unit via a tool that connects to the vehicle's OBD ports.
- Stationary Coding: Common in American cars, where the vehicle requires specific coding.
Advantages of the TPMS system
Maintaining proper tire pressure through the TPMS system has extensive benefits for both safety and economy:
- Security: Correct tire pressure ensures optimal performance, reduces braking distance and the risk of aquaplaning.
- Tire life: Appropriate tire pressure extends the life of the tire by reducing wear and tear and the risk of damage.
- Fuel efficiency: Correct tire pressure reduces the tire's rolling resistance and thus fuel consumption.
