What Is a TPMS Sensor?

A TPMS sensor (Tyre Pressure Monitoring System sensor) is a small electronic device fitted to your wheel. It measures tyre pressure and often tyre temperature, then wirelessly transmits that data to a display inside your vehicle.

The purpose is simple: detect abnormal pressure changes early so you can act before a tyre fails.

How TPMS Sensors Measure Pressure

Inside each TPMS sensor is a pressure transducer. This component detects air pressure inside the tyre and converts it into an electrical signal. The signal is processed and transmitted via radio frequency to your monitor.

• Pressure is measured in PSI or kPa
• Readings update continuously while driving
• Alerts trigger when pressure falls outside preset limits

How Temperature Monitoring Works

Many caravan TPMS sensors also track tyre temperature. Heat often increases before a failure. Excessive temperature can indicate:

• Under-inflation
• Overloading
• Wheel bearing issues
• Brake drag

Temperature monitoring provides an additional layer of safety, especially for long highway towing in Australia’s hot climate.

How Data Reaches Your Monitor

TPMS sensors transmit data wirelessly to a receiver in your vehicle. For caravans and trailers, the signal must travel from the rear wheels of the van to the cabin.

Quality systems are designed to maintain signal stability over this distance. Poor-quality sensors may drop out or provide inconsistent readings.

Internal vs External TPMS Sensors

TPMS sensors come in two main types:

• External sensors: Fit onto the valve stem. Easy to install and replace.
• Internal sensors: Mounted inside the tyre. Require tyre removal for fitting.

For caravan and trailer setups, many Australian owners prefer external sensors because they are easier to manage and replace individually.

Learn more in our detailed comparison: Internal vs External TPMS Sensors.

Why TPMS Matters for Caravan & 4WD Touring

Towing increases stress on tyres. Corrugations, long distances, heavy loads, and high temperatures all increase risk. A TPMS sensor acts as an early warning system.

• Detect slow leaks before they cause sway
• Identify overheating tyres
• Improve fuel efficiency through correct inflation
• Reduce risk of roadside tyre failure

Common Misconceptions About TPMS Sensors

• TPMS replaces manual pressure checks — it does not.
• All TPMS sensors are waterproof — they are not.
• Signal strength does not matter — it does when towing.

Ready to Upgrade?

Now that you understand how TPMS sensors work, the next step is choosing the right system for your touring setup.