How Does a TPMS Work

A TPMS or Tyre Pressure Monitoring System is an electronic device that continuously monitors the air pressure and temperature inside your tyres. The system is designed to alert the driver as soon as a tyre becomes underinflated, overinflated or overheats - allowing issues to be addressed before they develop into more serious problems.

When a tyre is not inflated to the correct pressure, it can lead to faster tyre wear, reduced fuel efficiency, poor handling and an increased risk of tyre blowouts. These risks become even more significant in demanding applications such as towing caravans, off-road driving and operating heavy vehicles like trucks and road trains.

Most aftermarket TPMS systems consist of three main components:

  • Sensors mounted on each tyre to measure pressure and temperature.
  • A display unit installed in the cabin to show live tyre data.
  • Wireless communication technology that transmits sensor readings to the display.

Whether fitted to a passenger vehicle, caravan, 4WD or truck, a TPMS provides peace of mind by helping to improve safety, reduce tyre-related breakdowns and extend tyre life.

How Does a TPMS Work?

A TPMS works by continuously measuring the pressure and temperature inside each tyre and wirelessly transmitting that information to a display in the vehicle cabin. This allows the driver to see real-time tyre data and receive instant alerts.

1. Sensors Detect Pressure and Temperature

The process begins with sensors installed on each wheel. These sensors can be mounted externally on the valve stem cap or internally inside the tyre, depending on the type of TPMS system.

Each sensor contains highly accurate electronic components that measure tyre pressure and tyre temperature.

Close-up of a car wheel with Promata external TPMS car sensor.

2. Sensors Wirelessly Transmit Data to the Display

Once the readings are collected, each sensor sends the data wirelessly using radio frequency (RF) signals to a display unit mounted inside the vehicle's cabin.

Every sensor has a unique identification code, allowing the display to distinguish between individual tyres and show exactly which wheel each reading belongs to. This is particularly important for vehicles with multiple axles, trailers and trucks where dozens of tyres may be monitored simultaneously.

Because the communication is wireless, there’s no need to run cables - making installation simple and reliable.

3. The Display Shows Live Data and Real-Time Alerts

The in-cab display receives the sensor data and presents it in an easy-to-read format. Drivers can view the exact pressure and temperature of each tyre at a glance.

The display updates continuously and if a tyre falls outside the pressure threshold or reaches a dangerous temperature - the system immediately triggers both visual and audible warnings.

4. Telematics for Remote Fleet Monitoring (Optional)

Advanced TPMS systems can also integrate with telematics platforms. This allows tyre data to be transmitted beyond the vehicle itself.

Instead of only displaying information in the cab, tyre pressure and temperature data can be beamed to a cloud-based platform where the data can be viewed remotely. This provides valuable insights into tyre health, maintenance requirements and potential issues.

How TPMS Displays Are Powered

The display unit is the central hub of a TPMS - receiving data from the sensors and showing it in real time. TPMS manufacturers offer several different power options to suit various vehicles and installation preferences.

Solar Powered Displays

Solar-powered TPMS displays feature a built-in rechargeable battery that is charged by an integrated solar panel. During normal daylight use, the panel continuously tops up the battery, allowing the display to operate without being permanently connected to the vehicle's electrical system.

This is one of the most popular power options because it offers a clean and simple installation. There are no cables to run through the dashboard, and the display can be positioned almost anywhere on the windscreen or dashboard.

Most solar-powered displays also include a USB charging port as a backup, ensuring reliable operation during extended periods of cloudy weather or if the vehicle is stored indoors.

Cigarette Plug Powered Displays

Some TPMS displays are powered using a 12V cigarette or accessory socket. The display plugs directly into the vehicle's power outlet and receives continuous power whenever the ignition is on.

This method provides a dependable power source and eliminates the need to monitor battery levels or rely on sunlight. It is especially useful for vehicles that spend long periods on the road or for drivers who prefer a "plug and play" solution.

The main drawback is that it occupies the accessory socket.

TPMS display monitor plugged into car cigarette plug.

Hardwired (Cable Powered) Displays

Hardwired TPMS displays are connected directly to the vehicle's electrical system, typically through the fuse box or another switched 12V power source.

TPMS display monitor showing tyre pressure & temperature data on truck dashboard.

This approach provides the most permanent and professional installation. The display receives constant power and all wiring can be hidden behind the dashboard for a clean factory-style appearance.

Hardwired systems are particularly popular in commercial vehicles, trucks and fleet applications where the display is expected to remain installed long term.