These are special sensors integrated into the wheel valve which, by transmitting information to the on-board computer, inform the driver of a loss of tyre pressure. As a result, you no longer need to physically check the pressure in each tyre - you are immediately provided with accurate data on the current tyre pressure.
From November 2014, every new car sold in the European Union countries must be equipped with a tyre pressure monitoring system. According to the regulation, the TPMS should detect a decrease in tyre pressure of 20% or a reduction to 1.5 bar (within 10 minutes for 1 wheel or 60 minutes for 4 wheels).
How does a tyre pressure sensor work?
There are two types of tyre pressure monitoring systems - direct and indirect. The more common option is TPMS sensors integrated into the pressure valve (direct system). A less commonly used option is pressure monitoring based on the ABS system (indirect system). In the former case, the signal transmission from the sensors to the computer takes place several times a minute, so the pressure information is very accurate.
When the car is stopping, changing speed and moving in traffic jams, the sensors are more likely to report the pressure condition than when driving at constant speed. For this reason, it is difficult to estimate their service life - as a rule of thumb, it is assumed to be around seven years or 150,000 km. Due to the need for perfect sealing, the sensors are housed in a suitable housing and it is not possible to replace their batteries.
Benefits of tyre pressure monitoring with TPMS sensors:
- improved vehicle handling and stability
- shorter braking distances
Reduced fuel consumption:
- lower fuel consumption
- lower emissions of pollutants
Slower tyre wear:
- longer tyre life
- less particulate matter in the air
- less waste (old tyres)
TPMS sensor programming
Installation alone does not yet make the tyre pressure sensor ready for use. It must first be properly programmed and activated. This is done through a coding process that allows the system to distinguish which wheel the radio signal is coming from. This service is carried out by the vulcanisation service using special equipment. It must be repeated each time the tyres or valves are changed.