TPMS 101: Understand Your Tire Pressure Monitoring System

Let's explore the TPMS together: What is it and how it keeps you safe on the road?

Have you heard of the Tire Pressure Monitoring System (TPMS)? This is an important safety feature in modern vehicles, but it can sometimes be challenging to understand.

Don’t worry; in this post, I will delve into the TPMS in detail to provide you with a complete awareness of this system. You will learn about:

  • What is the TPMS and how it works
  • The TPMS warning light and its significance
  • Pros and cons of two distinct types of TPMS
  • Essential factors to consider when replacing a TPMS sensor
  • ……

What Is a Tire Pressure Monitoring System (TPMS)

TPMS warning light on the dashboard

A Tire Pressure Monitoring System is an electronic system designed to monitor vehicles’ tire pressure. This system will trigger a warning light on the dashboard if your tire’s air pressure falls below 25% of the manufacturer’s recommended level, which you can find on the label of the driver’s side door jamb and in your owner’s manual.

The TPMS is a crucial component of modern vehicles, and it is required by law in many countries, including the United States. The National Highway Traffic Safety Administration (NHTSA) has mandated TPMS in all new cars and light trucks since 2007 to ensure that drivers are aware of their tire pressure levels at all times.[1]

Two Types of TPMS and Their Working Principles

There are two types of systems that are commonly used: the direct system (DTPMS) and the indirect system (ITPMS). One is sensor-based, which provides more easy-to-see tire pressure information. Another is more passive, stable, and gets less chance of mistakes.

Direct TPMS

This is a tire pressure sensor

Direct TPMS utilizes sensors installed in each tire to track real-time tire pressure. These sensors send the actual tire pressure readings to the vehicle’s computer. When the air pressure drops 25% below the recommended cold pressure set by the manufacturer, it will trigger a warning light on the dashboard. Some advanced systems can also display real-time tire pressure values (or even tire temperature) in the vehicle’s instrument panel or infotainment system. Direct TPMS sensor is designed to be accurate and reliable and can detect even the slightest change in tire pressure. This is vital because changes in temperature, altitude, and driving conditions can all affect tire pressure.


— Provides more accurate pressure values. 

— Allows for individual tire pressure readings.

— Can detect slow leaks and punctures.



— More expensive than ITPMS.

— Not repairable, must be replaced as a whole when it is bad.

— Difficult to replace it by yourself.


Indirect TPMS

Indirect TPMS operates through a different mechanism than direct TPMS. Instead of using pressure sensors within each tire, ITPMS works in conjunction with the vehicle’s Antilock Braking System (ABS), which is already present in most modern cars. The system can determine when one or more tires need to be inflated based on a comparison of the rotational speeds of each wheel. This is because an underinflated tire has a smaller diameter and spins faster than a properly inflated tire. The system then warns the driver with a warning light on the instrument panel.


— Does not require any additional hardware or sensors.

— Less need for programming and maintenance.

— More economical than DTPMS.



— Need to be reset manually after the inflation.

— Require recalibration when the tire size is changed.

— Unable to alert when all four tires are deflated evenly together.


Does Your Vehicle Have a TPMS

Can you find out the low-pressure warning light on this dashboard?

If your vehicle is equipped with a TPMS, the “low tire pressure” warning light on your dashboard will be activated when turning your key to the “on” position. You can also consult the owner’s manual or get in touch with the manufacturer to determine whether your car has TPMS.

Where Is TPMS Sensor Located

This tire pressure sensor is located inside each tire, on the rim, and attached to the valve stem

The answer to this question varies depending on your vehicle’s specific make and model. The tire pressure sensor is typically found within each tire, mounted on the rim, and attached to the valve stem. This is because the sensor must be near the tire to measure the air pressure accurately. You might have to take the tire off the rim in order to access the TPMS sensor.

It’s important to note that the tire pressure sensor is a critical component of your vehicle’s safety system and should only be tampered with or removed with proper training and equipment. Suppose you’re experiencing issues with your TPMS sensor. In that case, bringing your vehicle to a trusted mechanic who can correctly identify and fix the problem is best.  

What to Do if TPMS Warning Light Is On

Manufacturer’s recommended tire pressure is located on the driver’s side door jamb

If you are driving and suddenly see the TPMS warning light on your dashboard, it can cause concern and frustration. But don’t worry; there are a few things you can do to address the issue:

Check the tire pressure of all tires (including the spare tire) to ensure they fall within the recommended range. If the pressure is too low, fill your tires with air according to the manufacturer’s recommendations in the owner’s manual or on the driver’s side door jamb. If any punctures or damage to the tires, get them fixed or replaced as quickly as possible.

There could be a problem with the TPMS sensor if the warning light persists even after adjusting tire pressure. In this case, it is best to take your vehicle to a professional mechanic who can diagnose and fix the problem.

Ignoring the warning light can lead to potentially dangerous driving conditions and costly repairs in the long run. It’s crucial to address the issue and ensure your vehicle’s TPMS system is functioning properly. 

Benefits of TPMS

TPMS protects your tires from underinflation

Increased Vehicle Safety

One of the most significant benefits of TPMS is its increased vehicle safety. Proper tire inflation provides better traction and grip on the road, which is critical for maintaining vehicle control, especially in adverse weather conditions or emergencies. TPMS monitors tire pressure in real-time and alerts drivers when tire pressure drops below recommended levels, allowing for prompt corrective action. 

Improved Fuel Economy

Underinflated tires can cause a vehicle to use more fuel, as they have more rolling resistance, and the engine must work harder to propel the car. TPMS helps to maintain proper tire pressure, which can help optimize fuel efficiency and save money at the gas pump. 

Extended Tire Lifespan

When a tire is underinflated, its distorted shape creates more friction with the road, causing it to heat up and wear faster. This could eventually cause uneven wear and reduce the tire’s performance and longevity. However, with TPMS, you can keep your tires at the proper pressure, which helps you avoid costly tire repairs or replacements due to premature wear and tear. 

When to Replace Your TPMS Sensor

Like all parts, direct TPMS sensors can become damaged, worn out, or out of batteries, leading to inaccurate readings and potentially dangerous driving conditions.

So, when should you replace TPMS sensors? One common indicator is a warning light on your dashboard that won’t turn off even after checking and adjusting your tire pressure. Additionally, if your TPMS sensor is older than 5-7 years, it should probably be replaced. This is because the average lifespan of these sensors is around 5-7 years, depending on the model and manufacturer. Besides, factors such as exposure to extreme temperatures and damage from road debris can also cause sensors to fail prematurely. If you need help determining when to replace your TPMS sensor, it’s always best to seek advice from a reliable mechanic or dealership. They can evaluate your vehicle and provide you with recommendations for replacement based on your specific needs.

Remember to check the system regularly during routine maintenance appointments, as catching any issues early on can save you time and money in the long run.

How Much to Replace a TPMS Sensor

When it comes to replacing a tire pressure sensor, several factors can impact the cost. One of the most significant factors is the brand and model of your car. Some vehicles require specific types of sensors that may be more expensive than others. Additionally, some manufacturers have proprietary systems that can only be serviced by authorized dealerships, which can further drive up the cost.

Typically, the cost for a single replacement TPMS sensor can range from $50 to $250. Also, you have to consider the cost of installation. This can vary depending on where you take your car to have the sensor replaced. Some stores may offer a set fee for installation, while others may bill by the hour. On average, you can expect to pay between $20 and $60 for installation.

TPMS Cannot Completely Replace the Traditional Tire Gauge

Three types of tire pressure gauges: pencil/stick, dial, and digital

While technology has advanced in the automotive industry with the introduction of TPMS, it cannot completely replace the traditional tire gauge. It’s crucial to remember that some factors may also prevent you from obtaining accurate and timely readings through TPMS.

Indirect TPMS has limited accuracy and can not provide precise tire pressure readings. It may also be ineffective at detecting sluggish leakage.

Direct TPMS, on the other hand, sensors can malfunction or become damaged over time, leading to incorrect readings or no readings. Furthermore, extreme temperature changes can also affect tire pressure and the accuracy of your TPMS. For example, tire pressure can decrease in colder weather, which may trigger a TPMS alert. However, once the tires warm up, the pressure may return to normal, leading to a false alarm. 

It’s always a good idea to check your tire pressure regularly with a tire gauge, even if your vehicle has a TPMS. This way, you can ensure that your tires are properly inflated and avoid any potential safety hazards on the road.

For more information on maintaining tire pressure, please check out this blog post: Inflate to Greatness – Recommended Tire Pressure Ultimate Guide


Can I remove and reuse TPMS sensors?

The answer is YES. Remember that you can only reuse your old tire pressure sensors when they work well. As the sensors are delicate and easily damaged, you must carefully remove them from the wheels. Additionally, it would help if you considered the age of the sensors. Generally, a TPMS sensor lasts for 5- years. If your sensors have been used for a long time, replacing them the next time you change your tires may be a good idea. This will save you from repeating the removal and installation process and help ensure your vehicle’s tire pressure monitoring system functions correctly.

Can TPMS sensors drain car batteries?

NO. TPMS sensors are equipped with their own small batteries, which are designed to last for over five years. These batteries do not connect to the car’s electrical system. Furthermore, when the ignition is turned off, the TPMS receiver is also turned off, which means it is not actively monitoring the tire pressure. 

Can I change the battery of the TPMS sensor?

Yes, but I do not recommend you do that. Typically, the tire pressure sensor battery is not intended to be replaced. The battery is enclosed within the sensor’s plastic housing and sealed with a sealant. It is necessary to open the housing and remove the sealant to replace the battery, which can result in inaccurate readings or even failure of the TPMS sensor. It is not worth a try for most people.

Is it legal to disassemble a TPMS sensor myself?

This answer can vary from state to state and even country to country. In some states, driving with a malfunctioning TPMS sensor can result in fines or failed inspections, while in others, you may not be able to sell or register a vehicle without a properly working TPMS.

Therefore, it’s necessary to consult with your local Department of Motor Vehicles about the TPMS rules and regulations in your area. By following these guidelines, you can ensure that your vehicle is safe to drive and complies with all applicable laws.

Picture of Nick Wang

Nick Wang

Nick is the guy behind Tire Think. He’s been working as an engineer in the tire industry for 8 years, focusing on endurance indoor testing operations.
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