The tire pressure sensors Tires have become an almost invisible part of our cars' equipment, yet crucial for safety. Thanks to them, the driver receives a warning when a tire is low on air, reducing the risk of blowouts, improving grip, and helping to control fuel consumption.
What until now was seen as a harmless system is, however, beginning to raise doubts in the field of Privacy and cybersecurityA European investigation led from Spain has shown that these small smart valves can be used, without the user being aware, to track the movements of a vehicle through the radio signals they continuously emit.
TPMS: from road safety ally to potential tracking tool
The vast majority of cars on European roads today are equipped with Tire Pressure Monitoring System, known as TPMS (Tire Pressure Monitoring System). This system has been mandatory in new passenger cars in the European Union since 2014 and in other countries since the late 2000s, precisely because of its contribution to the road safety.
In direct TPMS systems, each wheel incorporates a small sensor, usually integrated into the valve, which measures in real time pressure and, in many cases, temperatureThis information is sent via radio to the vehicle's electronic control unit. When a pressure below the threshold set by the manufacturer is detected, a warning light illuminates on the instrument panel or a message appears on the central display.
In parallel, there are indirect TPMS systems, which do not use physical pressure sensors, but rely on the ABS system: if a tire loses air, its diameter changes and its rotational speed varies compared to the others. The car interprets this difference as a possible loss of pressure and issues a warning. In both cases, the vehicle bases part of its continuous tire condition monitoring on wireless signals.
So far, everything seems reasonable: more control over the tires means fewer surprises on the road. The twist comes when you analyze exactly how that data is sent, what extra information travels in each message, and who could capture it with relatively simple means, without having to tamper with the car.
The IMDEA Networks study: six million messages and 20.000 cars
A team of researchers from Madrid Institute for Advanced Studies IMDEA NetworksA company based in the Community of Madrid, with several European partners, decided to test the extent to which pressure sensors could be used for more than just warning of a puncture. During ten weeks of fieldworkThey deployed a network of low-cost wireless receivers near roads and parking lots.
Each of those receivers, which according to those in charge of the project cost around $100 or about €100It was dedicated to listening to the TPMS emissions of passing vehicles. No physical contact with the car or access to its internal electronics was necessary: it was enough to place the devices at strategic points where thousands of vehicles drive or park daily.
The result of that measurement campaign was conclusive. The researchers managed to collect more than six million messages from the pressure sensors more than 20.000 carsFrom that volume of data, the team was able to analyze patterns, verify the actual range of the signals, and assess whether it was possible to repeatedly identify specific vehicles.
According to research professor Domenico Giustiniano, one of those responsible for the work, the results demonstrate that The emissions from the sensors can be used to track vehicles. and reconstruct part of their movement routines, such as usual arrival times at work, frequent journeys, or travel habits.
Unencrypted identification codes: the gateway to tracking
The key element of the investigation is that the sensors not only send data from pressure and temperature, but also a unique identifier (ID) associated with each unit. This ID allows the vehicle itself to know which message corresponds to each wheel, but, when traveling in clear, unencrypted radio signalsIt also allows an external device to recognize the same car every time it passes by.
In practice, anyone with a general-purpose radio receiver, easily acquired online and configured to the appropriate frequencies, could capture those signals When a vehicle moves or stops within a certain distance. There's no need to see the license plate, install GPS beacons, or access the car's multimedia system: the information is transmitted automatically.
Tests by IMDEA Networks show that these signals can be collected at More than 50 meters from a distance, even if the car is inside a building, a garage, or hidden behind other vehicles. Because radio waves penetrate walls and obstacles, tracking does not depend on direct line of sight, unlike traffic cameras or license plate recognition systems.
Furthermore, the data transmitted by the sensors includes the pressure reading itself. From this information, it is possible to infer additional characteristics of the vehicle, such as whether it is usually heavily loaded, frequently tows a trailer, or whether it is a light passenger car or a heavier vehicle. The combination of Unique ID and physical parameters It opens the door to more detailed forms of surveillance than one might imagine when talking about something as commonplace as inflating tires.
For researchers, this scenario sets up a “hidden privacy risk” which until now had gone largely unnoticed. The big difference with other tracking technologies is that this one takes advantage of a system implemented for safety reasons, mandatory in modern cars, and which the driver cannot easily deactivate without rendering the vehicle non-compliant.
From road safety to cybersecurity: regulations that are lagging behind
The study's authors insist that TPMS was created with a clear objective: Avoid accidents caused by worn tiresThey fail to protect the vehicle from attacks or digital espionage. When these systems were designed years ago, concerns about automotive cybersecurity were almost nonexistent, and no one imagined that a simple pressure signal could be used to track a car through the city.
Today, however, connected vehicles are subject to increasingly strict cybersecurity regulations in Europe and other markets. Manufacturers must obtain specific certifications that guarantee a minimum level of protection against unauthorized access, insecure software updates, or remote manipulation of critical functions.
The problem, according to IMDEA Networks, is that Tire pressure monitoring systems are not included at this time. among the elements that require this level of protection. In other words: while doors like the car's internet connection or OTA updates are being secured, the "window" for pressure sensors remains open.
The researchers claim that Administration and industry They should review this regulatory gap and incorporate TPMS into the cybersecurity requirements for connected vehicles. Their proposal involves introducing encryption and authentication mechanisms in the sensor communications, so that a third party cannot easily interpret or associate the signals traveling between the wheels and the control unit.
Until that leap occurs, they warn, sensors will remain a simple objective for passive surveillanceIt is not necessarily a massive short-term risk, but it is a known vulnerability that could be exploited by anyone wanting to monitor entire fleets of vehicles or by anyone looking for movement patterns of specific people.
Tire pressure remains key to safety
Even with this underlying debate, experts remind us that maintaining the proper tire pressure It's essential for safe driving. The Spanish Directorate General of Traffic (DGT) insists that it's advisable to check your tires at least once a month and always before a long journey, using a tire pressure monitoring system. Reliable pressure gauge and following the values recommended by the manufacturer, which are usually shown on the door, frame or fuel tank lid.
Incorrect tire pressure alters the car's handling: if the tires are underinflated, rolling resistance increases, multiplying the fuel and CO2 emissions increase. At the same time, the rubber heats up more and wears unevenly, shortening its lifespan and reducing grip, especially in the rain.
When the pressure is too high, the central area of the tread bears almost all the contact with the asphalt, causing a Premature wear in the center and reduced ride comfort. Conversely, driving with very low tire pressure puts more strain on the shoulders, wearing down the sidewalls and increasing the risk of deformation that can lead to a blowout.
Manufacturers and public bodies agree that the tire is the single point of contact between the car and the roadThe condition of the tires directly impacts braking distance, cornering stability, and the effectiveness of other electronic driver assistance systems. ABS and stability control are of little use if the tires cannot properly transmit power to the road surface.
That's why, despite the advantages of TPMS and the warnings on the dashboard, specialists continue to recommend a Periodic manual and visual inspectionCheck for wear, cuts, and dents on the tire and ensure that the pressure is adjusted to the actual load of the vehicle, especially if you are going to travel with a full trunk or with several occupants on board.
Smart and connected tires: more data, more responsibility
While debate continues about how to better protect emissions from current TPMS, the tire industry is moving towards a new generation of smart tiresThese products integrate sensors inside the casing capable of recording not only pressure, but also temperature, tread wear level and, in some cases, tire behavior during driving.
Based on that, solutions such as connected valves that show the driver the exact pressure of each tire in real time, or platforms that allow the tire itself to "talk" to the vehicle's driver assistance systems to anticipate risky situations. Some manufacturers, such as Goodyear with its SightLine program, are working on technologies that interpret tire data to estimate the available grip level and the road conditions.
In everyday driving, this information can reach the driver through the instrument cluster, a head-up display, or connected apps. Among the advantages mentioned are the early detection of anomalies (pressure drops, excessive temperatures, significant wear), speed recommendations according to the type of tire fitted, or even Predictive Maintenancecalculating how many kilometers are left before the tires need to be replaced.
In the professional sector, many fleets already use solutions like these to better manage tire changes, reduce on-road incidents, and optimize fuel consumption. The combination of onboard sensors and advanced data analysis allows for scheduling workshop visits at the right time, instead of waiting for a problem to occur or changing tires purely as a precaution.
This entire ecosystem, involving manufacturers, networks of specialized workshops, and connected service providers, reinforces the idea that the tire has gone from being a passive component to a digitized and connected elementAnd, as with any device that generates and sends data, the more sophisticated the system, the greater the responsibility to protect the information it handles.
The photograph depicted in these works is that of some tire pressure sensors Essential for the safety and proper functioning of the car, these features also reveal a less visible aspect related to privacy. Amidst the obligation to check tire pressure every month, the benefits of monitoring systems, and the move towards fully connected tires, a clear message emerges for European manufacturers and regulators: if cars are going to increasingly communicate through their tires, it's crucial to ensure that this communication is done with adequate encryption and control measures so that this voice doesn't unknowingly become a tracking tool.
