Service Tire Monitor System (TPMS)

Your vehicle’s Tire Pressure Monitoring System (TPMS) is more than just a dashboard feature—it’s a built-in safety mechanism designed to keep you aware of your tire pressure in real time. Properly inflated tires are essential for optimal fuel efficiency, precise handling, and overall vehicle performance. But when the “Service Tire Monitor System” warning light suddenly appears, it can be confusing and even concerning.

What does this warning mean? Is it a simple fix, or does it signal a bigger issue? Ignoring it isn’t an option, as driving with incorrect tire pressure can lead to increased tire wear, reduced fuel economy, and even potential blowouts.

At Starling Buick GMC, we’re here to break it all down. In this guide, we’ll explain how TPMS works, the common reasons behind the warning, and step-by-step solutions to reset or repair your system. By the end, you’ll know exactly what to do the next time your TPMS light comes on—keeping you safe and confident on the road.

What Is a TPMS System and How Does It Work?

Your vehicle’s Tire Pressure Monitoring System (TPMS) is an essential safety feature designed to continuously monitor tire pressure and alert you if it falls below the recommended level. Proper tire inflation is critical for fuel efficiency, handling, braking performance, and tire longevity, making TPMS a key component in maintaining your vehicle’s overall safety and performance.

Types of TPMS: Direct vs. Indirect

There are two main types of TPMS systems, each functioning differently to detect low tire pressure:

1. Direct TPMS – This system uses individual pressure sensors located inside each tire, usually attached to the valve stem or mounted on the wheel. These sensors measure real-time air pressure and transmit data directly to your vehicle’s onboard computer. When the pressure in any tire drops below the manufacturer’s recommended level, the TPMS warning light appears on your dashboard. Direct TPMS is highly accurate but requires periodic sensor maintenance or replacement due to battery depletion over time.
2. Indirect TPMS – Instead of measuring air pressure directly, this system relies on your vehicle’s Anti-lock Braking System (ABS) sensors to track changes in wheel speed. When a tire becomes underinflated, its diameter slightly decreases, causing it to rotate faster than properly inflated tires. The system detects this variation and triggers the TPMS warning light. While indirect TPMS is less expensive and easier to maintain, it can sometimes be less precise, as factors like tire rotations or uneven wear can affect accuracy.

How Does TPMS Alert You to Low Tire Pressure? When your tire pressure drops too low, whether due to normal air loss, seasonal temperature changes, or a puncture, your TPMS will activate a warning light on the dashboard. This light usually resembles an exclamation mark inside a horseshoe-shaped tire outline.

While seeing the warning can be alarming, it’s a critical reminder that at least one of your tires may be underinflated. Ignoring the warning can lead to:

• Reduced fuel efficiency, as underinflated tires create more rolling resistance.
• Decreased handling and braking performance, increasing the risk of accidents.
• Premature tire wear, shortening the lifespan of your tires.
• A higher chance of tire blowouts, especially at highway speeds.

Because TPMS is a real-time monitoring system, it helps you act quickly to maintain proper tire pressure and avoid potential safety risks. In the next sections, we’ll explore the common reasons your TPMS warning might appear and how you can reset or service the system when needed.

Common Reasons for a Service Tire Monitor System Warning

If your vehicle’s Service Tire Monitor System warning appears on your dashboard, it means the TPMS has detected an issue with tire pressure or the monitoring system itself. While this warning can sometimes be resolved with a simple tire pressure check, other times, it may indicate a more serious issue requiring attention.

Low Tire Pressure: The Most Frequent Cause

One of the most common reasons for a TPMS warning light is low tire pressure. Tires naturally lose air over time, even in normal conditions. However, external factors can accelerate this process. A sudden drop in temperature, for instance, can cause the air inside your tires to contract, reducing pressure overnight. This is especially common during seasonal changes or in colder climates.

Additionally, normal driving wear, small punctures, or slow leaks can contribute to gradual air loss. If your TPMS light turns on, the first step should always be checking your tire pressure with a gauge and inflating the tires to the manufacturer’s recommended PSI.

Faulty or Dead TPMS Sensor: When the System Itself Fails

Each TPMS sensor relies on a small built-in battery to function. Over time, these batteries weaken and eventually die, typically after 5 to 10 years of use. When this happens, the sensor can no longer transmit accurate data, leading to a TPMS warning light even if your tires are properly inflated.

In some cases, the sensor itself may be malfunctioning due to internal damage, corrosion, or signal interference. If you’ve already verified that your tire pressure is correct and the warning light remains on, a professional diagnostic scan at Starling Buick GMC can determine whether a sensor needs to be replaced.

Tire Rotation or Replacement: A Reset May Be Needed

If you’ve recently had new tires installed, rotated, or replaced, the TPMS system may need to be recalibrated. This is because TPMS sensors are programmed to recognize specific positions on your vehicle, and changing tire locations can sometimes cause communication errors.

For example, if a front tire is moved to the rear without resetting the TPMS, the system may incorrectly detect a pressure issue or fail to update pressure readings. Many modern vehicles automatically recalibrate after a short drive, but some require a manual TPMS reset, which can be done using your vehicle’s onboard settings or a TPMS reset tool.

Damage to the TPMS Sensor: Physical Impact Matters

TPMS sensors, while durable, are not immune to damage. They are typically located inside the tire, attached to the valve stem or wheel assembly, making them vulnerable to accidental impact during tire changes. If a technician inadvertently breaks a sensor while mounting or dismounting a tire, it may stop working correctly.

Road debris, potholes, and harsh driving conditions can also contribute to sensor damage over time. If your TPMS warning appears after hitting a pothole or driving over rough terrain, it’s possible that a sensor has been dislodged or damaged.

While some TPMS warnings can be resolved with a simple tire inflation, others require sensor replacement or recalibration. Ignoring the warning can lead to uneven tire wear, poor fuel efficiency, and even potential safety hazards. If your TPMS light remains on despite checking your tires, it’s best to have your system inspected by a professional.

How to Perform a TPMS Reset (Step-by-Step Guide)

If your Tire Pressure Monitoring System (TPMS) warning light remains illuminated even after inflating your tires to the correct pressure, a system reset may be necessary. The reset process varies depending on the vehicle make and model, but the following steps provide general guidelines to help you troubleshoot and restore your TPMS functionality.

Step 1: Verify and Adjust Tire Pressure

Before attempting a reset, it is essential to first check and correct the tire pressure. Using a reliable tire pressure gauge, measure the air pressure in all four tires and compare it to the manufacturer’s recommended PSI (pounds per square inch). This information can typically be found in your owner’s manual, inside the driver’s side door panel, or on the fuel filler door.

If any tires are underinflated, add air until they reach the proper level. Likewise, if a tire is overinflated, release excess air to prevent uneven wear and handling issues. Once all four tires are properly inflated, turn on your vehicle and check if the TPMS warning light turns off. If the light remains on, proceed to the next step.

Step 2: Drive at a Consistent Speed

Many modern vehicles have a TPMS system that automatically resets itself after a certain period of driving. If your warning light persists after inflating your tires, try driving at a steady speed of 50 mph (80 km/h) or higher for approximately 10–15 minutes. This method allows the system to recalibrate and recognize the correct tire pressure levels.

After completing the drive, turn off the engine, wait a few minutes, and restart the vehicle. If the TPMS light turns off, the issue is resolved. However, if it remains on, move on to the next step.

Step 3: Use the TPMS Reset Button (If Available)

Some vehicles are equipped with a dedicated TPMS reset button that allows you to manually reset the system. If your vehicle has this feature, follow these steps:

1. Turn the ignition to the “On” position without starting the engine.
2. Locate the TPMS reset button, usually found beneath the steering wheel, in the glove compartment, or near the center console.
3. Press and hold the reset button until the TPMS warning light begins to blink.
4. Release the button and drive the vehicle for a few minutes to allow the system to recalibrate.

If the light does not turn off after performing this reset, your vehicle may require a more advanced troubleshooting process.

Step 4: Disconnect the Battery (Last Resort)

If none of the previous methods work, disconnecting the battery may serve as a final reset option. However, this step should be used with caution, as it resets all electronic settings in your vehicle, including your clock, radio presets, and potentially other stored configurations.

To perform a battery reset:

1. Turn off the vehicle and open the hood.
2. Using a wrench, carefully disconnect the negative terminal (-) of the battery.
3. Leave the battery disconnected for 10–15 minutes to allow the vehicle’s computer to reset.
4. Reconnect the battery terminal and securely tighten it.
5. Start the vehicle and check if the TPMS light has turned off.

If the TPMS light is still on after performing these steps, it is likely that one or more TPMS sensors are faulty, damaged, or have a dead battery, requiring professional diagnosis and servicing.

When to Seek Professional Help

If your TPMS warning light remains on despite following these troubleshooting steps, it may indicate a more complex issue such as a malfunctioning sensor, damaged valve stem, or a system calibration error. In such cases, it’s best to consult a certified technician who can perform a diagnostic scan and determine whether a sensor replacement or system reprogramming is necessary.

Tire Pressure Sensor Location – Where to Find It?

The Tire Pressure Monitoring System (TPMS) sensors are small yet crucial components designed to track air pressure inside your tires. These sensors are strategically placed inside each wheel, typically attached to the valve stem. They continuously monitor tire pressure and send real-time data to your vehicle’s onboard computer, allowing you to receive immediate warnings if the pressure falls below the recommended level.

In most vehicles, the TPMS sensors are built into the valve stems themselves, meaning they serve a dual purpose: allowing air to enter the tire and transmitting pressure data. However, in some models, the sensors are mounted directly inside the wheel rather than on the valve stem. These internal-mounted sensors are usually clamped or strapped onto the rim and require professional equipment to access or replace.

While most drivers assume that TPMS sensors are only located in the four main tires, it’s important to note that some vehicles also have a sensor in the spare tire. This is particularly common in trucks, SUVs, and off-road vehicles that rely on full-size spare tires. If your TPMS warning light remains on even after inflating and inspecting your four primary tires, don’t overlook the possibility that your spare tire may be triggering the alert.

Understanding where these sensors are located is key, especially when performing tire changes, rotations, or replacements. If a sensor becomes damaged or dislodged during service, it can lead to incorrect pressure readings or persistent TPMS warnings. If you’re uncertain about the placement of your TPMS sensors, consult your owner’s manual or visit Starling Buick GMC for a professional inspection.

Preventative Maintenance for Your TPMS System

A properly functioning TPMS system not only enhances safety but also helps improve fuel efficiency, tire longevity, and overall driving performance. Like any vehicle component, TPMS sensors require regular maintenance to ensure they continue working correctly. Here are some essential steps to keep your TPMS system in top condition:

1. Check Your Tire Pressure Monthly

Even if your TPMS light isn’t illuminated, it’s still a good habit to manually check your tire pressure at least once a month. TPMS sensors are designed to alert you when tire pressure falls below a certain threshold, but they don’t always detect minor fluctuations that can still affect vehicle performance. Temperature changes, slow leaks, and normal air loss over time can all contribute to gradual pressure drops.

Using a high-quality tire pressure gauge, check the pressure in all four tires and inflate them to the manufacturer’s recommended PSI, which can be found in your owner’s manual or on a label inside the driver’s door. Keeping your tires properly inflated helps prevent uneven wear, poor handling, and increased fuel consumption.

2. Inspect Your TPMS Sensors for Damage

Although TPMS sensors are built to withstand harsh driving conditions, they are still vulnerable to physical damage, corrosion, and electronic malfunctions. If you notice a slow air leak, difficulty inflating a tire, or frequent TPMS warnings despite proper pressure levels, it could indicate a damaged or failing sensor.

Common causes of TPMS sensor damage include:

• Accidental impact during tire mounting, dismounting, or rotation.
• Exposure to harsh weather conditions, road salt, or extreme temperatures.
• Valve stem deterioration, which can lead to air leaks and sensor malfunctions.

If you suspect a TPMS sensor issue, schedule a professional diagnostic check at Starling Buick GMC to prevent further problems.

3. Replace TPMS Sensors When Needed

TPMS sensors are powered by small built-in batteries that typically last 5 to 10 years, depending on usage and environmental factors. Once the battery dies, the sensor can no longer transmit data, triggering the Service Tire Monitor System warning on your dashboard. Since TPMS batteries are sealed inside the sensors, the only solution is sensor replacement.

To avoid unexpected failures, consider proactively replacing TPMS sensors when:

• They reach the 5- to 10-year mark (especially if you’re experiencing intermittent warnings).
• You replace your tires—installing new sensors along with new tires can save on labor costs.
• A sensor is damaged or no longer transmitting data, even after resets.

Routine TPMS maintenance ensures accurate tire pressure monitoring, safer driving, and fewer unexpected issues on the road. If your vehicle’s TPMS needs servicing, the team at Starling Buick GMC is ready to assist with expert inspections, sensor replacements, and system recalibrations to keep your tires performing at their best.

FAQs About TPMS and Tire Pressure Sensors

Understanding how your Tire Pressure Monitoring System (TPMS) works is essential for maintaining vehicle safety and performance. While TPMS helps monitor tire pressure automatically, many drivers still have questions about its function, maintenance, and what to do when the warning light appears. Below are answers to some of the most frequently asked questions about TPMS and tire pressure sensors.

How often should I check my tire pressure?

Even though TPMS provides automatic alerts, it’s still recommended to check your tire pressure at least once a month and before any long road trip. TPMS sensors typically activate only when tire pressure drops below a certain threshold, meaning small pressure losses may go undetected.

Additionally, seasonal temperature changes can significantly affect tire pressure. Colder weather causes air to contract, leading to lower pressure, while warmer temperatures cause air to expand, potentially leading to overinflation. Regular manual checks ensure that your tires remain at the optimal PSI, preventing uneven wear, poor handling, and decreased fuel efficiency.

Can I drive with a TPMS warning light on?

Technically, yes—you can still drive your vehicle with the TPMS warning light on, but it’s strongly discouraged. A TPMS alert indicates that at least one of your tires is underinflated or there is a system malfunction. Driving with low tire pressure can lead to poor vehicle handling, increased braking distances, and reduced fuel efficiency.

More importantly, ignoring the warning can increase the risk of tire blowouts, excessive tire wear, and potential damage to the suspension system. If the TPMS light appears, check your tire pressure as soon as possible. If inflating the tires doesn’t resolve the issue, schedule a professional inspection to ensure your sensors and system are functioning correctly.

Do all vehicles come with a TPMS system?

Most modern vehicles—specifically those manufactured in 2008 or later—are required by law to be equipped with a TPMS system. This mandate was introduced as part of the TREAD Act (Transportation Recall Enhancement, Accountability, and Documentation Act) in response to safety concerns over tire-related accidents.

However, if you drive an older model vehicle (pre-2008), it may not have a built-in TPMS. In this case, manual tire pressure checks are crucial for maintaining proper inflation levels. For added convenience and safety, aftermarket TPMS kits are available for older vehicles, allowing you to upgrade your system and receive real-time tire pressure alerts.

Maintaining a properly functioning TPMS ensures a safer, smoother, and more fuel-efficient drive. If you have any concerns about your tire pressure sensors, TPMS warning lights, or overall tire health, visit Starling Buick GMC for a professional inspection and servicing.

Conclusion

Your TPMS system is an important tool for maintaining safety and performance on the road. If you ever see a Service Tire Monitor System warning, don’t ignore it! Checking your tire pressure, performing a reset, and keeping up with TPMS maintenance can prevent bigger issues down the road.

If you need TPMS service, new sensors, or professional tire maintenance, the experts at Starling Buick GMC are here to help. Schedule an appointment today and drive with confidence!