What Is the TPMS Sensor on Your Car and How Does It Work?

If you experience a tire blowout, it can lead to a dangerous situation. This is why a Tire Pressure Monitoring System (TPMS) is an essential safety feature. This technology provides valuable information to help maintain your tires and prevent blowouts.

A TPMS sensor, also known as a tire pressure sensor, is a key component of this system. How do these sensors work in a car, and how can you program them? Let's explore further.

What Is a TPMS Sensor?  

A TPMS sensor is an electronic device that monitors the air pressure in a vehicle's tires. It continuously measures tire pressure and alerts you if the air pressure drops to dangerously low levels.

These sensors are standard in all new vehicles. In fact, a law passed by Congress mandates that all cars manufactured after 2008 must be equipped with a TPMS sensor.

But what if you own an older vehicle that lacks this technology? If your car doesn't have a TPMS sensor, you can easily purchase an aftermarket option. For instance, wireless tire pressure monitoring systems are available that plug into your car's cigarette lighter, allowing you to add this important safety feature.

How Do Tire Pressure Sensors Work on a Car?  

The operation of a Tire Pressure Monitoring System (TPMS) depends on the type of system in use. There are two main types: direct TPMS and indirect TPMS, each functioning in a distinct manner.

Direct TPMS: This system features a sensor mounted on each wheel of the vehicle. These sensors actively monitor the air pressure in each tire. If the pressure in any tire drops below 25 percent of the manufacturer-recommended level, the sensor communicates this information to the car's computer, triggering a warning light on the dashboard.

Indirect TPMS: This system relies on the wheel speed sensors integrated into the car's antilock braking system (ABS). When a tire is under-inflated, it will roll slower than properly inflated tires. The sensors detect discrepancies in wheel speeds and assume that a tire is low on air. In response, the system alerts the car's computer, which then activates the dashboard warning light.

How Do TPMS Sensors Get Power?  

TPMS sensors are powered by batteries designed to last several years. However, these batteries do not last indefinitely and will eventually lose their charge.

Typically, the battery is integrated into the TPMS sensor assembly, making it difficult to replace independently. As a result, if the battery dies, you will need to replace the entire tire pressure monitoring system.

Are TPMS Sensors Vehicle-Specific?

Yes, most TPMS sensors are vehicle specific.

In cars with factory-installed TPMS sensors, the sensors are always vehicle-specific. Automakers get these systems from specific suppliers, and the supplier can vary from model to model. If you use an incompatible TPMS sensor, it likely won't work with your car's system.

What about aftermarket sensors designed for cars that weren't factory-equipped with a tire pressure monitoring system? In many cases, these aftermarket sensors are vehicle specific as well.

How to Program a Tire Pressure Sensor  

To program a tire pressure sensor yourself, follow the instructions provided with a compatible TPMS programming and diagnostic tool.

Some TPMS sensors require programming before use, as they come blank and need specific information about the vehicle's make, model, and year. To complete this process, simply follow the menu steps on your TPMS programming and diagnostic tool.

For many people, it may be more convenient to have a service technician handle the programming. If you'd prefer not to do it yourself, you can have your tire pressure sensor programmed at a tire shop or auto repair facility.

What Is the Best Tire Pressure Monitoring System?  

The best tire pressure monitoring system (TPMS) is one that is compatible with your vehicle.

Many aftermarket systems are designed to work exclusively with vehicles from specific automakers. With numerous excellent options available, begin your selection process by ensuring that the technology is compatible with your vehicle's make and model.

If you are considering replacing a factory-installed TPMS, it's important to replace it with the same system originally installed by the manufacturer.

Final Thoughts  

If your car is equipped with a TPMS sensor, it's crucial to replace the system when the battery dies to ensure your tires remain properly inflated.

For older cars lacking a tire pressure sensor, investing in an aftermarket system is advisable. These systems are readily available and easy to install, providing a quick way to monitor the condition of your tires.