TPMS (Tire Pressure Monitoring System) monitors your tire pressure and warns you before a slow pressure loss becomes dangerous or expensive. Since November 2014, every new car registered in the EU must have such a system on board. This guide explains what exactly this requirement means, how direct and indirect systems work, how to identify which system your car has, what to consider when switching to winter or accessory wheels, and when a sensor needs to be replaced.
Note: zrshop carries over 120 TPMS articles, including vehicle-specific OE sensors from SCHRADER, HUF, and Continental/VDO, programmable universal sensors from ALCAR and CUB, and service kits with valve cores and seals. The examples in this guide are taken from this real assortment; the binding vehicle assignment is always provided on the product page of the respective sensor.
1. Since when has TPMS been mandatory and for which vehicles?
The mandate comes from EU Regulation No. 661/2009 on the general safety of motor vehicles. It prescribes tire pressure monitoring in two stages: since November 1, 2012, for newly type-approved passenger car models, and since November 1, 2014, for all newly registered passenger cars of class M1, i.e., ordinary passenger cars including motorhomes of this class. The technical requirements for the systems are regulated by UN Regulation No. 141, which replaced the earlier ECE-R 64.
Practically, this means: A car first registered from November 2014 has a TPMS ex works, and this system must be functional. Deactivating a factory-installed safety system is not an option; a permanently illuminated TPMS warning can be considered a defect during the main inspection. For older vehicles without a factory-installed system, there is no retrofit requirement.
Important for truck-like pickups: Vehicles registered as N1 (light commercial vehicles) were not subject to the passenger car mandate of the 2009 regulation. Many pickups and vans nevertheless have a TPMS installed ex works; in this case, it must also remain functional. Whether your vehicle is classified as M1 or N1 can be found in the registration certificate.
2. Direct TPMS: Sensors in the Wheel
A direct system measures pressure where it originates: in the wheel. A sensor is located in each wheel, usually mounted on the valve, which detects pressure and temperature and sends it to the control unit via radio. The vehicle thus knows the actual pressure of each individual wheel and, depending on the model, can even display the values per wheel.
The strengths of the direct system: It also detects a slow, uniform pressure loss on all four wheels, it warns even when stationary, and it provides actual measured values instead of an estimate. The downside: The sensors are wear parts. Their permanently installed battery usually lasts five to ten years, depending on mileage and manufacturer, after which the complete sensor is replaced because the battery alone cannot be changed. In addition, each wheel set requires its own sensors, more on this below.
There are two types of sensors, and both can be found in the zrshop range. Vehicle-specific OE sensors, such as the SCHRADER OE series, are the counterpart to the original equipment part and fit a defined vehicle list. Programmable universal sensors, such as the ALCAR Sensor or the CUB UniSensor2, cover a great many vehicles depending on the protocol, but must be configured for your vehicle with a programming device before installation. For workshops and frequent changers, universal sensors are practical; for a single wheel set, the appropriate OE sensor is often the more direct route.
3. Indirect TPMS: Measurement via Wheel Speed
An indirect system does not require sensors in the wheel. It uses the existing wheel speed sensors of ABS and ESP: If a tire loses pressure, its rolling circumference becomes minimally smaller, meaning the wheel rotates slightly faster than the others. Modern systems also evaluate vibration patterns and thus detect even uniform pressure loss on multiple wheels better than earlier generations.
The strengths: no sensors, no sensor batteries, no additional costs for wheel changes. A second set of wheels for winter does not require any TPMS hardware. The downside: The system does not display actual pressure values, it only detects deviations above a certain magnitude, and after every pressure correction or wheel change, you have to recalibrate it via the onboard menu or a reset button. If you forget to reset after inflation, the system will compare with incorrect reference values in the future.
4. Which system does my car have?
The most reliable source is the owner's manual, where the system is described, usually including the reset or learning procedure. Two quick clues also help. First, the display: If your car shows individual pressure values per wheel, it is certainly a direct system; if it only warns generally with a warning light, it could be either. Second, a look at the valve: Metal valves with a union nut often indicate a sensor behind them, but there are also direct sensors on rubber valves, so the valve alone is not proof.
As a rough guide: Many VW Group models use indirect systems, many French, Asian, and American manufacturers, and most premium models use direct systems. However, never rely on the brand alone for ordering, but check the vehicle list of the specific sensor on the product page. If you are unsure, zrshop's wheel consultation will tell you the right way based on your vehicle data.
5. Wheel change, winter wheels and accessory rims: what the TPMS does
With an indirect system, it's simple: change wheels, set pressure correctly, reset the system, done. With a direct system, the second wheel set needs its own sensors, otherwise monitoring will fail and the warning light will remain on. Those planning winter wheels or new alloy wheels should therefore include the four sensors from the outset, including programming, if the vehicle does not automatically adopt the new sensor IDs. How programming works and the three available methods are explained in the separate guide Programming TPMS Sensors.
One point that is often overlooked: the service kit. The valve core, seal, and union nut of a sensor valve age and corrode, so they should be replaced with every tire change. Service kits are available for this purpose in the TPMS range, sorted by sensor manufacturer. A seized metal valve that breaks off when loosened can otherwise cost a complete sensor.
Important note: When buying complete wheels or mounting tires, pay attention to whether your vehicle has a direct system and whether sensors are ordered or relocated. A wheel set without sensors on a vehicle with direct TPMS means a permanently illuminated warning and, depending on the inspector, a defect during the main inspection.
6. When does a sensor need to be replaced?
The three most common reasons: the battery is dead after years, the valve was damaged during assembly, or a curb or impact damage affected the sensor. A dead or defective sensor reports itself, depending on the vehicle, with a permanent warning light, an error message, or a missing wheel value in the display. The complete sensor is always replaced, and then the new sensor ID must be made known to the vehicle.
Useful to know: If new tires are being fitted anyway and the sensors are already seven or eight years old, it's worth replacing all four at once. This way, mounting costs are only incurred once, and you avoid one sensor after another failing in the next two years. Suitable sensors by vehicle can be found in the TPMS section, and the tire pressure basics in the guide Setting tire pressure correctly.
View TPMS sensors and service kits by vehicle
7. Warning in the display: how to react correctly
If the TPMS warning lights up, stop at the next opportunity and check all four tires, first by visual inspection, then with a pressure gauge. A noticeably soft tire with a visible foreign object is a case for the workshop, not for continuing the journey. If the display shows only a small deviation, correct the pressure to the target value from the fuel cap or door jamb table and observe whether the warning reappears. If it comes back without an apparent reason, this indicates a creeping damage or an aging sensor. The correct target pressure for your vehicle and why it differs when loaded is explained in the guide Tire pressure by vehicle model.
A special case is the temperature effect: The pressure physically drops in cold weather, by about 0.1 bar per ten degrees Celsius temperature drop. Therefore, TPMS warnings accumulate on the first cold autumn mornings, without a defect being present. Correct the pressure, acknowledge the warning or reset the system, done.
FAQ about the Tire Pressure Monitoring System
Is TPMS also mandatory for winter wheels?
The regulation obliges vehicle manufacturers to deliver new cars with a functional system. For vehicles with a direct system, a winter wheel set without sensors means that monitoring fails and the warning light remains on permanently, which can be considered a defect during the main inspection. With an indirect system, the winter wheel set does not require any hardware, only a reset after the change.
Can I simply deactivate the TPMS?
No. It is a mandatory safety system that must remain functional. Aside from the legal aspect, you lose the warning of slow pressure loss, one of the most common causes of tire damage at high speeds.
How can I tell if my sensor will soon be empty?
The remaining runtime can be read out with a TPMS diagnostic device; many workshops check this during tire changes. Without reading out, age is the best indicator: From about seven years, the probability of failure increases significantly.
Do universal sensors really fit my car?
Programmable universal sensors cover many, but not all, vehicles, and they must be programmed for your vehicle before installation. The vehicle list of the respective sensor on the product page is decisive. If in doubt, send your vehicle data to our advisory service before ordering.
Does the TPMS also warn of too high pressure?
Direct systems know the actual measured value and, depending on the vehicle, also report significant excesses, while indirect systems primarily react to the deviation between the wheels. Therefore, when inflating, do not rely on the TPMS, but on the pressure gauge.
Does it always have to be re-learned after a tire change?
With an indirect system, a reset in the onboard menu is sufficient. With a direct system, it depends on the vehicle: Some automatically adopt known sensors after a few minutes of driving, others require programming via a diagnostic device or a learning drive. The detailed procedures are described in the learning guide.