Replacing Tyre Pressure Sensors

Tyre Pressure Monitoring System (TPMS) sensors play an important role in modern vehicle safety by continuously monitoring tyre pressure and alerting drivers when pressures fall outside the recommended range. Most TPMS sensors are powered by small built-in batteries designed to last years under normal driving conditions.

The replacement process can vary depending on the type of TPMS sensor fitted to the vehicle. Some are from the vehicle manufacturer while others are aftermarket. Some systems use internal sensors mounted inside the wheel, while others rely on external sensors that are screwed onto the tyres valve stem. Understanding the type of sensor installed is the first step in choosing the correct replacement method.

OEM Internal TPMS Sensors

OEM (or vehicle manufacturer) internal TPMS sensors are fitted inside the wheel. These sensors contain sealed internal batteries that are not designed to be replaced separately. Once the battery reaches the end of its lifespan, the entire TPMS sensor must be replaced to restore proper system operation.

When replacing an internal sensor, it is important to use the correct sensor type specified for the vehicle. This usually means sourcing genuine or OEM-compatible sensors designed for brands such as Toyota, Isuzu, Ford, Mazda, Hyundai or whichever manufacturer the vehicle was built for. Using the correct replacement sensor helps ensure accurate tyre pressure monitoring and reliable communication with the vehicle’s system.

Because the sensor is mounted inside the wheel, replacement requires the tyre to be removed from the rim using professional tyre fitting equipment. After installation, the new sensor must also be paired or programmed to the vehicle so the TPMS control module can recognise it correctly.

Aftermarket Internal TPMS Sensors

Aftermarket internal TPMS sensors are a popular alternative to vehicle manufacturer sensors and are commonly used in retrofit TPMS kits for passenger vehicles, caravans, trailers and trucks. Many of these systems come pre-mapped to specific tyre positions, allowing the external display unit to identify each wheel location automatically once the sensors are installed. This makes setup simpler and helps drivers quickly identify which tyre requires attention if a pressure warning occurs.

Like OEM internal sensors, aftermarket internal sensors use sealed built-in batteries that are not replaceable. When the battery eventually reaches the end of its service life, the entire sensor unit must be replaced rather than repaired.

Because these sensors are installed inside the wheel and tyre assembly, professional installation is recommended. The tyre must be removed from the rim, the sensor securely mounted and the wheel resealed and balanced correctly before use.

External Sensors

External TPMS sensors are designed with convenience in mind and are commonly fitted to the outside of the valve stem. Unlike many internal factory-fitted sensors, these units typically use replaceable button-cell batteries, allowing the sensor to continue operating by replacing the battery only without needing to replace the entire unit when the battery runs flat.

In most cases, replacing the battery is a straightforward DIY task that can be completed easily at home. The sensor housing can be opened to access the button battery, making maintenance quick and cost-effective for vehicle owners.

This simplicity makes external TPMS sensors a practical option for a wide range of vehicles, including 4WDs, caravans, trailers and heavy trucks.