TPMS Sensors

TPMS stands for Tyre Pressure Monitoring System. A TPMS is an electronic system designed to monitor the air pressure inside the tyres of a vehicle. The TPMS sends the air pressure data back to the driver in real time either by a gauge, a pictogram display or a simple low-pressure warning light.

There are two main reasons that TPMS has been introduced:
1. - Avoiding traffic accidents due to under-inflated tires by early recognition of the malfunction of tyres.
2. - Reducing rolling resistance to increase overall fuel efficiency.

There are two main types of TPMS. Direct systems or Indirect systems.
1. - Direct TPMS uses sensors inside each tyre that are attached to the tyre valves. The sensors monitor the pressure of each individual tyre and send a wireless signal back to the vehicle computer. The pressure data is then displayed on the vehicle’s dashboard. If the pressure drops below a preset level it will issue a warning to the driver so they can have that specific tyre checked.
2. - Indirect TPMS uses data from ABS or wheel-speed sensors to determine a loss of tire pressure. If the difference between one and another tyre exceeds a certain tolerance, the monitoring system will indicate tyre pressure loss.

TPMS has now become such an important issue due to recent legislation changes regarding it’s use in the United Kingdom and European Union. Important facts about TPMS are below:
1. - As of 1st November 2012, all new-type vehicles are required by EU law to have a pressure based tyre pressure monitoring system installed. This applies to the road wheels, not the spare. This system can be direct or indirect TPMS.
2. - By 1st November 2014, all new passenger vehicles had to have TPMS installed by the manufacturer
3. - The law is not currently retrospective, and does not apply to older vehicles and this law applies to passenger vehicles only, with no more than 7 seats
4. - TPMS is now part of the annual vehicle test (MOT), and applies to all newly registered cars from January 1st 2012. This means that a car with a faulty TPMS will fail the vehicle test since January 2015
5. - Until 2015, a faulty TPMS was only an advisory and listed on the testing certificate (UK). Different European countries may interpret the EU legislation differently. So please refer to your own European country legislation