What Does TPMS Mean? Everything You Need to Know

TPMS stands for Tire Pressure Monitoring System. This system keeps track of your tire pressure and lets you know if it gets too low by showing a warning light on your dashboard.

Think of TPMS as a helpful safety feature that ensures you don’t drive on dangerously low-pressure tires. Low-pressure tires can make your car harder to control and cause tire damage or even blowouts.

According to the National Highway Traffic Safety Administration (NHTSA), tire-related issues contribute to around 11,000 crashes annually. Low tire pressure affects handling and can lead to blowouts, particularly at highway speeds.

A study by WheelRight found that one in four vehicles in Britain has at least one underinflated tire. This leads to bad fuel economy and heightened risk.

What is a Tire Pressure Monitoring System (TPMS)?

A Tire Pressure Monitoring System, or TPMS, is a system in your car that checks the air pressure in each tire. If any tire’s pressure drops too low, the TPMS light on your dashboard comes on to warn you.

This is a common feature in newer cars. TPMS keep drivers safe by signaling dangerously low tire pressure, which can lead to accidents and faster tire wear.

Types of TPMS: Direct vs. Indirect

Let’s look at two main types of Tire Pressure Monitoring Systems, each working a bit differently:

• Direct TPMS uses sensors inside each tire to measure the actual air pressure. If the pressure in any tire drops below a safe level, it sends a signal to your car’s computer. This lights up the TPMS warning. Direct TPMS is highly accurate, but it’s also more complex and may cost more to maintain. Because the sensors have batteries that eventually need replacing.
• Indirect TPMS doesn’t measure the air pressure directly. Instead, it relies on wheel speed sensors that monitor how fast each tire rotates. If one tire has low pressure, it will rotate differently, and the system will notice that and trigger the TPMS light. Indirect TPMS is less precise since it doesn’t provide exact pressure readings, but it’s simpler and often cheaper.

To sum up, Direct TPMS offers precise pressure readings. But it can be more expensive to maintain because of sensor replacements.

Indirect TPMS is simpler and often less costly but may not provide information as accurate as direct TPMS. Choosing between the two often comes down to your vehicle’s needs and how much you value real-time precision.

 

How Does TPMS Work?

For direct TPMS, each tire has a sensor that reads the air pressure and sends that information to the car’s computer. When one tire’s pressure is too low, the computer triggers the TPMS warning light.

With indirect TPMS, the system checks if each tire is spinning at the same rate. Think of it like a cyclist noticing that one wheel suddenly feels harder to pedal than the other. This shows a problem without needing a pressure gauge.

If a tire’s pressure drops, it has a slightly different circumference. So, it spins differently than a properly inflated tire. The system picks up this change and warns you.

What to Do If the TPMS Light Comes On?

If your TPMS light comes on, it’s a sign that one or more of your tires could be low on air. Here’s what you should do:

1. Check tire pressure. Find a safe spot, use a gauge to check each tire’s pressure, or stop by a gas station.
2. Fill tires as needed. Add air to any low tires until they reach the recommended pressure. You can find recommended pressure in your car’s manual or inside the driver’s side door.
3. Reset the system. In some cars, TPMS will reset automatically, while others may require a manual reset.

 

Why is My TPMS Light On? Common Causes

Your TPMS light might turn on for a few different reasons:

• Low Tire Pressure: This is the most common reason. Tires naturally lose air over time, or you might have a small leak.
• Temperature Changes: Cold weather often lowers tire pressure. Because air contracts in the cold, which can activate the TPMS light. When it’s warm again, the pressure might stabilize.
• Sensor Malfunction: TPMS sensors have small batteries that typically last 5-10 years. If one battery is low, the TPMS light could come on, signaling it may be time for a replacement.
• Recent Tire Rotation or Replacement: If you rotated or replaced your tires, the system might need to be reset.

 

How Serious is the TPMS Warning Light?

Driving with the TPMS light on is risky because it usually means one or more of your tires is low on air. This affects how well your car handles and could lead to a blowout.

Low tire pressure can also increase tire wear, making them wear out faster. If the light comes on, it’s best to check your tires right away.

Why Does My Tire Pressure Light Stay on When Tires Seem Fine?

If your TPMS light stays on even after you’ve checked your tires, a few things could be going on:

Sometimes, temperature changes or minor pressure fluctuations can keep the light on.

The sensors can wear out or have battery issues, especially if they’ve been used for several years.

When you get new tires or rotate your existing ones, your system might need recalibration to get back to working normally.

How to Reset Your TPMS?

Resetting your TPMS depends on your car model, but here are a few common ways to do it:

• Drive at a steady speed. For some cars, driving at about 50 mph for 10 minutes can reset the system.
• Use the TPMS reset button. Some cars have a TPMS reset button. Press and hold this button until the TPMS light blinks, then release it. Start the car and let it run for about 20 minutes to complete the reset.
• Refer to the manual. If these steps don’t work, check your owner’s manual for specific instructions.

Interactive Troubleshooting Flowchart

Start Here:

1. TPMS light is on → Check tire pressure.

• If pressure is normal → Proceed to reset TPMS.
• If low → Inflate tires to recommended levels.

2. If TPMS light blinks → Check for sensor.

Blinking light often means a sensor malfunction. Check for sensor battery issues, especially if your vehicle is older.

3. If light persists → Seek professional help.

Consider recalibration or replacement.

Click to download TPMS self-check guide

When to Service or Replace TPMS Sensors

TPMS sensors are usually designed to last a long time, but they may need servicing or replacement in these cases:

If they’re over 5-10 years old, the batteries in the sensors might start to die, so replacement is a good idea.

A hit, like hitting a pothole or a curb, could damage the sensor.

Some emergency sealants can harm the sensors. If you’ve used a sealant, it’s worth having the sensors checked afterward.

Frequently Asked Questions

1. Do I need to reset TPMS when I get new tires?

Yes, it’s often necessary to reset the TPMS after getting new tires. After resetting, the system can accurately monitor the new tire setup. Tire changes may slightly alter tire diameter, which affects how the system reads the pressure.

2. How long do TPMS sensors last?

Typically, TPMS sensors last between 5-10 years. The battery inside each sensor powers it, so once the battery dies, you’ll need to replace the sensor.

3. Can cold weather affect my TPMS?

Yes, cold weather can cause the air inside your tires to contract, which can lead to low pressure and trigger the TPMS light. Often, the light goes off once the tires warm up or if you add a little air.

4. What should I do if my TPMS light is blinking?

A blinking TPMS light usually means there’s an issue with one of the sensors. This could mean the sensor is damaged, malfunctioning, or nearing the end of its battery life. Getting it checked by a professional is best.

5. Can tire sealants damage TPMS sensor?

Yes, certain tire sealants can harm TPMS sensors. If you use a sealant to fix a flat, have the sensors inspected afterward to make sure they’re still functioning correctly.

6. Is it safe to use aftermarket TPMS sensors?

Yes, you can use aftermarket sensors as long as they’re compatible with your car model. However, some aftermarket sensors may need special tools to install or sync with your car’s system. You may need professional installation.

7. Can TPMS detect which specific tire is low?

Direct TPMS often show which tire is low because each tire has its own sensor that sends its data separately. Indirect systems, however, typically only show a general warning without identifying a specific tire.

8. Do I need to reset TPMS after rotating my tires?

Yes, tire rotation can affect TPMS, especially in indirect systems. Resetting helps the system recalibrate to detect pressure changes accurately.

9. Can I use aftermarket TPMS sensors?

Aftermarket sensors can work well if compatible with your car. However, you may need professional installation to ensure proper functionality.

Common Myths About TPMS

Myth 1: “TPMS replaces manual checks.”

Fact: TPMS is a backup, not a replacement. Regular checks are essential, as TPMS won’t always detect slow leaks.

Myth 2: “Only direct TPMS provides accurate readings.”

Fact: While direct TPMS is precise, indirect TPMS is often sufficient for regular maintenance, especially in mild climates.

Myth 3: “TPMS prevents blowouts.”

Fact: While it warns of low pressure, TPMS doesn’t prevent blowouts. Proper tire maintenance is crucial.

Environmental Impact

Proper tire pressure increases fuel efficiency by up to 3%. By maintaining optimal pressure, drivers can reduce CO₂ emissions.

For every 10% under-inflation, fuel consumption increases by roughly 1%. TPMS helps minimize these emissions by keeping tire pressure consistent, benefiting the environment and drivers’ wallets.

Conclusion

TPMS is an essential system that keeps you safe by alerting you to low tire pressure. This is crucial for good car performance, safety, and even fuel efficiency.

Knowing how it works, why the light might come on, and what to do if it does can help you avoid issues and keep your tires in great shape.

Check your tire pressure regularly in changing weather. This is a simple but effective way to stay safe and ensure your TPMS system continues to work correctly.

Key Takeaways:

• TPMS, or Tire Pressure Monitoring System, alerts you when tire pressure is too low. This ensures safer driving and better tire performance.
• There are two types: Direct TPMS, which measures actual tire pressure, and Indirect TPMS, which tracks tire rotation speed.
• If the TPMS light comes on, check tire pressure and add air if needed, or reset the system if you’ve resolved the issue.
• Regular TPMS sensor checks can prevent unexpected warnings, especially in cold weather, which affects tire pressure.
• Accurate TPMS readings help improve fuel efficiency, tire longevity, and road safety.