TPMS sensor - A complete guide to the tire pressure monitor system

TPMS-sensor: En komplett guide til dekktrykkmonitorsystemet

What is a TPMS sensor, how does it work, and what do you gain from installing a tire pressure monitoring system? This article answers all your questions about tire pressure sensors and introduces the handiest TPMS ever made for large vehicles: El-Watch’s patented Tap ‘n Tell.

TPMS sensors first appeared in European luxury cars in the 1980s. US car manufacturers adopted it in the mid-90s. In 2007, TPMS became mandatory for all US cars, buses, trucks, and passenger vehicles under 10.000 pounds (4536 kg).

In 2014, the European Union made TPMS mandatory in all new passenger cars. The amendment was further expanded in July 2022. Then it became compulsory for all new trucks, trailers, buses, and coaches to equip a working tire pressure monitoring system.


What is TPMS?
How does a TPMS sensor work?
Tap ‘n Tell makes tire pressure monitoring easier than ever!
Do I really need TPMS sensors?
Increased safety with each tire pressure sensor
How a tire pressure monitor system prevents transport standstills
TPMS for more sustainable transport
TPMS is easier than ever with IoT
Is tire pressure sensor fault a problem? (TPMS sensor replacement)
Why is a tire pressure monitor system a good investment?
FAQs about TPMS sensors

What is TPMS?

TPMS stands for Tire Pressure Monitoring System. This system electronically surveils each tire with TPMS sensors. It keeps track of Tire pressure and reports changes or irregularities to the drivers.

There are two types of tire pressure monitoring systems: Direct and indirect. Direct TPMS utilizes tire pressure sensors installed in each wheel. Indirect TPMS estimates tire pressure by analyzing wheel speed, acceleration, driveline data, etc.

How does a TPMS sensor work?

El-Watch’s wireless TPMS sensors communicate by IoT to smartphones or other devices. Our robust tire pressure sensors are easily installed inside each tire by magnets. The sensors transfer data to a gateway underneath the vehicle, which uploads it directly to the cloud.

Under normal conditions, the TPMS sensors measure tire pressure every ten seconds and send reports every two minutes. Should the tire pressure drop more than 0.2 bars within two minutes, a notification is instantly sent to the driver.

El-Watch’s TPMS sensors measure both tire pressure and tread temperature. The latter is a feature particular to our tire pressure sensors. Since the thread has road contact, reading its temperature/friction tells us how well the tires grip and can alert drivers about disaligned axles, overload complications, or brake failures.

Magnet installation means no tools are required to refit or change sensors, and no chance of air leakage from sensor attachment on the outside filling valves.

IoT allows the TPMS to be active 24/7. This ensures that drivers have total control and never need to be delayed due to unforeseen tire pressure circumstances, even if the tire leaks air through the weekend or at night.


Neuron THS Tyre Health Sensor (TPMS)

Neuron Tyre Health System (THS), er en ny måte å overvåke, analysere og administrere dekkhelsen til store kjøretøy på.

Tap ‘n Tell makes tire pressure monitoring easier than ever!

El-Watch’s patented tap ‘n tell TPMS solution makes tire monitoring more effortless than ever. All you need to do is to scan the vehicle’s QR code with your smartphone. This alerts the tire pressure sensors and tells them to listen for ultralow pressure shocks.

Then you lightly hit each tire two times with a hammer. After hitting a tire, you check your phone to see that the TPMS sensor registered the hit. This way, you can install tire pressure sensors in all tires for the truck and trailer before they go on the vehicle and register them later. The best part is that no expensive tools are required for the job, only your good old hammer.

As such, tire changes, sensor installation, and tire pressure monitoring are easily manageable for all drivers and service personnel. The tap ‘n tell method leaves no room for confusion about which sensor is placed in which tire.

Check out our video about TPMS tap ‘n tell to see how easy it is done.

Do I really need TPMS sensors?

By US and European law, most private and commercial vehicles are required to have a functioning tire pressure monitoring system. Such laws are spreading globally, first and foremost, to prevent accidents by early detection of dangerous tire conditions.

Moreover, TPMS monitoring promotes fuel-efficient driving, hinders unexpected transport standstills, and decreases CO2 emissions. Simply put, installing TPMS sensors is the sensible and responsible thing to do.

Increased safety with each tire pressure sensor

Mandatory TPMS in the US came about because of the so-called Firestone and Ford tire controversy. Faulty tires in Ford Explorers and other cars led to increased fatal car accidents in the mid-90s, which resulted in TPMS legislation.

In 2003, the US National Highway Traffic Safety Administration reported that 414 fatalities, 10,275 non-fatal injuries, and 78,392 crashes occurred annually due to flat tires or blowouts.

In 2016, the NHTSA reported that up to 11.000 car accidents were tire-related, 630 of which led to the loss of life. Though fatalities were up from 2003, the total number of casualties was significantly lowered.

It is hard to discern to what degree TPMS has prevented car accidents, but fatal car accidents in the EU have been halved since the tire pressure monitoring systems became mandatory in private cars in 2014.

Since then, technology has come a long way. TPMS sensors are more accurate, IoT makes monitoring more accessible, and tire-related accidents are more efficiently prevented and avoided. But wait, there are more benefits to gain from TPMS.

How a tire pressure monitor system prevents transport standstills

TPMS streamlines transport in more ways than you might think. For one, tire pressure monitoring enables early tire failure detection. This allows drivers to plan maintenance beforehand and ensure that tire pressure leaks don’t cause delays or standstills.

We call this process predictive maintenance, a cornerstone of El-Watch’s services.

Secondly, TPMS sensors ensure that all tires have optimal air pressure at all times. This promotes optimal fuel consumption and prolongs the tires’ lifespan. Correct pressure levels also ensure that other truck parts are not worn out faster than necessary.

A ten percent underinflated wheel equals a one percent fuel increase. The NHTSA has estimated that correct air pressure saves small trucks (presumably 4.5 tons) 13 liters of fuel annually.

In other words, the average truck driver will not save much in fuel consumption. However, when TPMS is mandatory on most US and EU vehicles, the total savings become substantial. And fuel consumption directly connects to CO2 emissions.

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TPMS for more sustainable transport

Like fuel consumption, individual CO2 reductions are not all that much. By ensuring appropriate tire pressure, CO2 emissions in light transport vehicles are reduced by 0.2 percent and heavy-duty vehicle fleets by 0.3 percent.

These relatively small savings become considerable when adding up the total from all light transport vehicles in the US and everything up to heavy-duty vehicle fleets in the EU. When TPMS becomes mandatory all over the world, it will matter.

So far, the USA, EU, China, and South Korea have introduced mandatory TPMS. Japan, India, Russia, Malaysia, the Philippines, and Indonesia are other countries moving towards similar legislation.

TPMS is easier than ever with IoT

Some companies and drivers have previously abstained from installing TPMS because of the added workload. Demanding installation, numerous tire changes, and frequent trailer changes made TPMS sensor administration aggravating.

At El-Watch, we’ve developed a solution that eliminates all these issues. We call it the Neuron Tyre Health System (THS). The combination of IoT and our patented tap ‘n tell solution (described above) makes TPMS administration more effortless than ever.

All you need to do is to pair your phone with your vehicle by a QR code and tap the tires to register the sensors at work in each tire. After that, the TPMS sensors will alert you of any tire pressure changes by email, push notification, or by an optional in-cabin warning light.

The QR scan connects the tire pressure sensors with the truck gateway; the wheel taps register which tires each sensor monitors. If you change the trailer or the tires, all you must do is register the change in your app.

As for the installation, our robust sensors are attached by a magnet. If you happen to forget to place the sensor at the regular wheel change, the tires don’t need to come off the rim for installation. Just slide the tire to the side and place the tire pressure sensor inside to fix it to the tire cord.

Check out our Neuron THS video to see how it is done.

Is tire pressure sensor fault a problem? (TPMS sensor replacement)

In private cars with pre-installed TPMS and a dashboard light, tire pressure sensor faults might be problematic due to electronic control unit (ECU) complications. This is not a problem for truck drivers when installing El-Watch’s IoT TPMS sensors.

Because our sensors operate on a separate system directly connected to your device, any irregularities are easily detected. Our TPMS sensors are designed to be robust. They mainly need to be replaced when the battery runs out after about five years.

TPMS sensor replacement is done in a matter of minutes. All you need to do is to remove the old tire pressure sensor from the inside of the tire and fix the new one to the tire cord.

The El-Watch Neuron Tyre Health System is designed to eliminate any tire pressure monitor problem we could think of. We aimed to make an easily manageable TPMS for anyone. We are proud to say that our customers are satisfied with the result.

Why is a tire pressure monitor system a good investment?

TPMS is a good investment because it keeps drivers, passengers, and other motorists safe. Even though fuel savings are limited, TPMS makes tires last longer, decreases the need for regular maintenance, and keeps vehicles reliable for longer.

This all adds to substantial savings in the long run, not just from a financial aspect, but you also save yourself from many unnecessary grievances. No matter how insignificant, every accident is still an annoyance that is best avoided.

Last but far from least, investing in a tire pressure monitoring system helps reduce CO2 emissions. You won’t stop global warming on your own. None of us will, but together we can make a difference.

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FAQs about TPMS sensors

Before rounding off this article on TPMS sensors, THS, and tire pressure monitoring, we’ll address a handful of the most frequently asked questions. If you require more info about our services or TPMS, feel free to contact El-Watch anytime.

Where is the TPMS sensor located?

TPMS sensor location is inside the tires. They are commonly attached to the back end of the valve. Sometimes, the valve stem must be changed to a valve type that can accommodate a TPMS sensor.

El-Watch’s TPMS sensors are located on the inside of the tire itself. They are attached by a magnet that sticks to the cord inside the rubber. This makes installation, replacement, and administration much quicker and easier. It also ensures the most accurate tire thread temperature measuring possible.

How do I install a new TPMS sensor?

Depending on your valve stem design, you can install the tire pressure sensor directly on the valve’s end inside the rim. Sometimes the valve must be changed to a type that can attach a sensor.

The El-Watch TPMS sensor is installed by placing it inside the tire where the magnet sticks to the tire cord. This video shows you how.

Can I replace TPMS myself?

That depends on how handy you are. If your TPMS sensor type attaches to the tire valve, you must first gain access to the inner rim of the tire. Then you must undo the screw or nut that holds the sensor in place, remove it, and attach the new one.

It’s a relatively simple operation, but it can be troublesome to inexperienced «mechanics». Changing El-Watch’s TPMS is much less bothersome since it only requires access to the inner tire. Removing and replacing magnetic sensors are child’s play.

How long does it take to replace a TPMS sensor?

A professional mechanic can replace a TPMS sensor in 15 minutes. If you are doing it yourself, it might take an hour or more, depending on your type of sensor. Valve-attached TPMS sensors take much longer to change than sensors attached by magnets.

Do you need to reset TPMS after changing to new tires?

TPMS sensors should always be recalibrated after tire changes, be it a complete tire change, tire rotation, or sensor updates. Certain manufacturers recommend resetting your TPMS sensors every time you fill your tires with air.

How do you test a TPMS sensor?

Most TPMS sensors are easily tested by a diagnostic tool. The El-Watch THS sensors are either tested by the tap ‘n tell method or by checking the app on your smartphone. You will be notified in your app if the batteries are running low.

How do you reset a tire pressure sensor?

How to reset a tire pressure sensor varies. In private cars, there is usually a button underneath the steering wheel. If you installed the sensor yourself, you might have to use a diagnostic tool or the sensor app in combination with the tap ‘n tell method.

How many TPMS sensors do I need?

You need at least one tire pressure sensor per moving wheel. This is because each sensor monitors the tire pressure of one wheel. In addition, you’ll need a gateway to process and transfer the data from the TPMS sensors.

If trailers or wheels are frequently changed, efficiency increases if you install tire pressure sensors on all wheels. Then you only need to register your changing of wheels or trailer in the app.

Can I drive with a TPMS sensor light on?

You should not drive with your tire pressure sensor light on or after getting a notification in your app. Stop and check your tire pressure as soon as possible. Driving with underinflated or overinflated tires is not safe. Also, it wears down your tires prematurely.

Why is my TPMS sensor light on, but the tires are fine?

Tire pressure sensor light or app notifications sometimes indicate TPMS sensor battery depletion, a bug in your ECU, or on rare occasions, a tire pressure sensor fault. Even if your tires are OK, these things should be checked at your earliest convenience.

If you liked this article, you’ll find many interesting ones on our webpage. How about this one, about how wireless sensors enable a sustainable manufacturing industry?


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CARiD: What Is the History of Tire Pressure Monitoring Systems?
Goodyear: EU General Safety Regulation
MTD: The real benefit of TPMS
National Highway Traffic Safety Administration: Evaluation of the Effectiveness Of TPMS in Proper Tire Pressure Maintenance
National Highway Traffic Safety Administration: Tire Pressure Monitoring System FMVSS no. 138
ONiO: Batteryless IoT sensors in Tyre Pressure Monitoring Systems (TPMS)
TNO: Study on Tyre Pressure Monitoring Systems (TPMS) as a means to reduce Light Commercial and Heavy-Duty Vehicles’ fuel consumption and CO2 emissions
United Nations Economic Commission for Europe: TPMS Fitment and Tyre Inflation Pressures Field Study EU 2016/2017


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