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What is TPMS? - Tutorial Media File
A tire pressure monitoring system or TPMS is an electronic system for monitoring the air pressure in a vehicle tire and automatically transmitting a warning to the driver in the event of an under or over inflated tire. These systems have been legislated to be progressively installed on all new passenger carrying US vehicles and a similar move is taking place worldwide. The Media File opens within your standard browser using our inbuilt web page media player. The duration of the file is just under 6.30 minutes.
What is a Tire Pressure Monitoring System?
A tire pressure monitoring system or TPMS is an electronic system for monitoring the air pressure in a vehicle tire and automatically transmitting a warning to the driver in the event of an under or over inflated tire. These systems have been legislated to be progressively installed on all new passenger carrying US vehicles and a similar move is taking place worldwide.
The majority of systems use Direct tire sensors which transmit real time tire pressure information to the driver of the vehicle either via either a dashboard display or a warning light. The sensors are physical pressure transducers which are attached to the back of the valve stem or are in a form which is banded to the wheel. The sensors are manufactured by International companies such as Schrader, Siemens, TRW, Pacific, Lear and others. There is no common technical standard for the sensors and the OE's and suppliers have generated a multitude of sensor designs.
The sensors also transmit data such as their unique sensor ID, temperature and pressure, battery life and other diagnostic information. This data is sent to the Engine Control Unit (ECU) or specific receiver on the vehicle. Those vehicles which have graphical displays of the TPMS positions can then show on which wheel there is a problem.
Why is there a need for Tire pressure monitoring?
Tire Pressure Monitoring helps drivers to properly maintain their vehicle tires, improves vehicle safety and aid fuel efficiency. The National Highway Traffic Safety Administration (NHTSA) in the US has estimated that 533 fatalities per annum are caused by tire defects in road accidents. Adding TPMS to all vehicles could avoid 120 of the 533 yearly victims and save as many as 8,400 injuries every year. Sécurité Routière (the French Institution for Road Safety) estimates that 9% of all fatal road accidents are attributable to tire under-inflation and the German DEKRA estimated that 41% of accidents with physical injuries are linked to tire problems. Tires leak air naturally and over a year a typical new tire can lose between 3 and 9 psi. As most drivers only check their tires at service intervals and when problems occur there is significant scope for fuel savings and efficiencies.
Given this background and prompted by the Firestone recall (where one hundred deaths due to roll-overs were attributed to tire separation) the US Federal government has legislated for the mandatory use of TPMS. The TPMS mandated by the US law must warn the driver when a tire is under-inflated by as much as 25%.
What is a tire pressure monitoring tool?
There is no common standard for the TPMS sensors with variations including frequencies, modulations, data structure, communications protocols, mechanical fitment and many other factors.
When TPMS is installed and tested in the car plant by Bartec the process includes:
- The TPMS sensors are attached to the wheel during the Wheel and Tire assembly process
- The wheels are attached to the vehicle. This is the first time at which the TPMS can be clearly associated with the vehicle
- Fixed radio antennas are used to extract the unique IDs (and other data) of the TPMS, associate them with their wheel position on the car and the Engine Control Unit (ECU) can then be programmed with this data
- The car is then run through Rolls Test where the system is tested
Similarly the car dealer or tire shop needs to have a portable TPMS tool available to test the TPMS and read the wheel sensor ID and program the car's ECU in the event of TPMS battery failure, broken sensor/valve, or other repair or replacement of wheels and sensors for custom wheels, winter tires, tire rotation etc. The tool needs to be able to turn out the TPMS warning light.
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