A Complete Guide to Tire Pressure Monitoring Systems (TPMS)

08 Sep.,2025

 

A Complete Guide to Tire Pressure Monitoring Systems (TPMS)

Key Takeaways

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  • TPMS monitors tire pressure and alerts drivers when it drops below the recommended level to improve safety and efficiency.
  • There are two types of TPMS: direct TPMS uses sensors inside tires for accurate readings, while indirect TPMS relies on wheel speed sensors.
  • Common TPMS warnings occur due to low tire pressure, faulty sensors, battery failure, or system malfunctions.
  • Regular tire pressure checks, sensor replacements, TPMS resets, and proper maintenance ensure accurate readings and system longevity.

What is a Tire Pressure Monitoring System (TPMS)?

A Tire Pressure Monitoring System (TPMS) is an electronic system that continuously monitors the air pressure inside a vehicle’s tires and alerts the driver when the pressure falls below the recommended level.

Why is TPMS Important?

  • Prevents Accidents: Proper tire pressure ensures better traction and reduces the risk of blowouts.
  • Improves Fuel Efficiency: Underinflated tires create more rolling resistance, increasing fuel consumption.
  • Extends Tire Lifespan: Correct tire pressure prevents uneven wear, increasing the longevity of tires.
  • Enhances Vehicle Handling: Properly inflated tires improve braking and overall driving performance.

Types of Tire Pressure Monitoring Systems

There are two main types of TPMS:

Direct TPMS

Direct TPMS (dTPMS) uses pressure sensors inside each tire to measure air pressure and send real-time data to the vehicle’s onboard computer.

How Direct TPMS Works

  • Sensors mounted inside each tire measure air pressure and temperature.
  • The data is transmitted wirelessly to the TPMS control module.
  • If the pressure drops below the recommended level, the TPMS warning light on the dashboard illuminates.

Advantages of Direct TPMS

✔️ Provides accurate and real-time pressure readings.
✔️ Can detect pressure loss in individual tires.
✔️ Works independently of tire size or type.

Disadvantages of Direct TPMS

❌ Sensors require battery replacement after a few years.
❌ More expensive to install and maintain.
❌ Reprogramming may be needed after tire replacement.

Indirect TPMS

Indirect TPMS (iTPMS) does not use pressure sensors. Instead, it relies on the vehicle’s Anti-lock Braking System (ABS) and wheel speed sensors to detect changes in tire pressure.

How Indirect TPMS Works

  • When a tire loses pressure, its diameter decreases, causing it to rotate faster than other tires.
  • The wheel speed sensors detect this discrepancy and send a warning signal to the TPMS module.
  • The TPMS light turns on when a significant difference in wheel rotation is detected.

Advantages of Indirect TPMS

✔️ Less expensive compared to direct TPMS.
✔️ No sensor batteries to replace.
✔️ Works well with different tire brands and sizes.

Disadvantages of Indirect TPMS

❌ Less accurate than direct TPMS.
❌ Cannot measure actual tire pressure, only detects relative changes.
❌ Requires recalibration after tire rotation or replacement.

How to Identify a TPMS Warning Light

When TPMS detects low tire pressure, a yellow warning light shaped like a tire cross-section with an exclamation mark appears on the dashboard.

Common TPMS Warning Signs

  • Steady TPMS Light: Indicates at least one tire has low pressure.
  • Flashing TPMS Light: Suggests a malfunction in the TPMS system, requiring inspection.

Common Causes of TPMS Warnings 

Low Tire Pressure

Tires naturally lose pressure over time due to changes in temperature or small air leaks. Cold weather can cause pressure to drop quickly, triggering the TPMS warning light.

Faulty TPMS Sensors

TPMS sensors typically last between 5-10 years before they wear out. When a sensor stops working, it can send incorrect signals or fail to detect low tire pressure.

Battery Failure in Direct TPMS Sensors

Direct TPMS sensors rely on small built-in batteries that eventually run out. When the battery dies, the sensor stops transmitting data, leading to a TPMS warning light.

Tire Rotation or Replacement Without Resetting TPMS

Some vehicles require TPMS recalibration after tire rotation or new tire installation. If not reset, the system may give inaccurate readings or keep the warning light on.

Electrical Issues in the TPMS Module

A malfunction in the TPMS control unit can prevent sensors from sending pressure data. Wiring issues or software glitches may also cause false warnings or system failure.

How to Fix TPMS Warnings 

Check Tire Pressure

Use a reliable tire pressure gauge to check the PSI of all four tires. If the pressure is low, fill each tire to the manufacturer’s recommended level to turn off the TPMS warning light.

Reset the TPMS System

Many vehicles have a TPMS reset button, usually located under the dashboard or in the glove box. Hold the button until the TPMS light blinks, which signals that the system has been recalibrated.

Replace Faulty Sensors

If the TPMS light stays on even after inflating the tires, one or more sensors may be faulty. A tire shop can diagnose the issue and replace any malfunctioning sensors if needed.

Inspect the TPMS Module

A malfunctioning TPMS control unit can cause false warnings or system failure. A professional mechanic can inspect and repair electrical faults to restore proper TPMS function.

Maintaining Your TPMS for Long-Term Use 

Regularly Check Tire Pressure

Even with TPMS, manually checking tire pressure once a month ensures accuracy. A tire pressure gauge helps detect slow leaks or minor pressure drops before they trigger a warning.

Replace TPMS Sensors When Needed

Most direct TPMS sensors have a battery life of 5-10 years and will eventually stop working. Replacing them on time prevents false alerts and keeps the system functional.

Keep the TPMS System Calibrated

After tire rotations or new tire installations, the TPMS system may need recalibration. Follow the vehicle manual to reset the system and ensure accurate pressure readings.

Avoid Harsh Driving Conditions

Hitting potholes, rough roads, or curbs at high speeds can damage TPMS sensors inside the tires. Driving carefully on uneven surfaces helps extend sensor lifespan.

Use Compatible Tires

Some aftermarket or oversized tires may not work well with TPMS sensors. Before purchasing new tires, check compatibility to avoid TPMS errors or malfunctions.

Frequently Asked Questions 

Can I Drive With the TPMS Light On?

Driving with a TPMS warning light is unsafe. Check tire pressure immediately to prevent accidents.

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How Much Does It Cost to Replace TPMS Sensors?

Replacing a TPMS sensor costs between $50-$250 per sensor, depending on the brand and labor costs.

Can I Install TPMS in a Car That Doesn’t Have It?

Yes, aftermarket TPMS kits are available and can be installed by a mechanic.

Do All Cars Have TPMS?

Since , TPMS has been mandatory in all passenger vehicles sold in the U.S. However, older cars may not have it.

Does Cold Weather Affect TPMS?

Yes, tire pressure decreases in cold weather, often triggering TPMS warnings. Checking and adjusting pressure in winter is essential.

Conclusion 

A Tire Pressure Monitoring System (TPMS) is a vital safety feature that enhances vehicle performance, fuel efficiency, and tire lifespan. Understanding its functions, common issues, and maintenance practices ensures a safer and more efficient driving experience.

If your TPMS warning light appears, always inspect tire pressure promptly. Regular maintenance and timely sensor replacements will keep your TPMS functioning optimally.

By keeping your tire pressure in check, you not only enhance vehicle safety but also save money on fuel and tire replacements.

Tire Pressure Warning Light Came On | What to Do

Big changes between high and low temperatures that happen in the fall can trigger an alert on your dashboard, one that may leave some drivers wondering what to do next.

If you see a symbol that resembles a cutaway tire with an exclamation point, it means your tire-pressure monitoring system has issued a warning. Falling temperatures can trigger the system because tire pressure declines with the thermometer.

Pull over as soon as you can and check your tire pressure. (Some systems give a generic warning, while others give a specific pressure.) Driving on improperly inflated tires can affect fuel mileage (underinflated tires are less efficient) and how the car rides and steers, particularly in an emergency situation.

And remember that the warning light can come on and then go off due to temperature changes, including heat put in the tire through driving.

“Just because the light went out doesn’t mean your tires are properly inflated,” Rogers says.

Of course, regular tire-pressure checks are always a good idea, regardless of what your tire-pressure monitoring system says.

“You still need to check your tire pressure monthly,” says Ryan Pszczolkowski, who runs tire testing at Consumer Reports. “And remember, TPMS is a warning system, not a maintenance tool.”

The system does exactly what you’d think: It keeps track of the air pressure in each of your car’s tires. It works independently in each wheel, and sets off a warning light (the tire/exclamation point icon) on the instrument cluster if the pressure is too low.

The typical trigger happens when the pressure is 25 percent lower than the manufacturer’s recommended cold-tire pressure, Pszczolkowski says, which can be measured when the tires have been sitting for at least 3 hours. You can find the recommended pressure level by checking your owner’s manual or by reading the sticker on the driver’s doorjamb.

There are two main flavors of tire-monitoring systems: direct systems and indirect systems.

“The vast majority of TPM systems in the U.S. are the direct type, which has a pressure sensor/transmitter mounted to the wheel,” Rogers says. “The sensor/transmitter is most often attached to the end of the valve stem on the end that is out of sight, inside the tire’s air chamber. A small number of direct systems have the sensor/transmitter separate from the valve stem.”

These are attached to the inside of the wheel with a metal strap.

Indirect systems get their information by comparing how the vehicle’s tires are turning in tandem, Rogers says.

“These indirect systems use the wheel-speed sensors [part of the antilock brake system] to monitor the revolutions of all four tires as the vehicle moves,” he says. “The central processor of the indirect system uses advanced algorithms to sense small changes in tire rotation speed created by different inflation pressures among the four wheel positions.”

The cost depends in part on the work you’re having done, says Rogers of Tire Rack. If you’re already getting new tires, the sensors will be within easy access and take only a short amount of time and labor to change.

“It becomes a lot more expensive to replace when you aren’t having a tire change done,” he says.

The average price for a direct sensor can range from $45 to $65 for most common vehicles, based on listings at tirerack.com.

Rogers says that some “niche vehicles” might have sensors that cost hundreds of dollars, but these very specialized sensors are extremely uncommon.

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