The tire pressure sensor measures the air pressure inside your tires and sends that data to your car’s onboard computer. The system then displays the pressure on your dashboard and activates a warning light if any tire drops below the recommended level.
A tire pressure sensor can fail for several reasons, but one of the most common causes is heat. Since the sensors are located inside the wheel, they’re constantly exposed to high temperatures, which can damage their delicate electronic components over time.
Understanding the symptoms of a bad tire pressure sensor and what to do when one fails can help you maintain proper tire pressure, improve safety, and avoid unnecessary tire wear.
In This Article:
Symptoms Of A Bad Tire Pressure Sensor (TPMS)
The most common symptom of a bad tire pressure sensor (TPMS) is the TPMS warning light appearing on your dashboard. You might also notice incorrect or inconsistent tire pressure readings, or even false low-pressure alerts when your tires are properly inflated.
Because the sensor is an electrical component, it can wear out over time. Factors such as heat, dirt, dust, and inconsistent power supply can all reduce its accuracy and performance. When this happens, you may start to notice small but clear changes in how your vehicle monitors tire pressure.
Below is a detailed list of the signs of a bad or failing tire pressure sensor to help you identify the problem early.
1. Low Air Pressure in the Tires
The function of the tire pressure sensor is to alert you when the tire is low. So if you find that your tires are flat or you have difficulty driving your car, the tire pressure sensor has failed or is not working properly. The sensor must be in proper operating condition to make a correct assessment.
Therefore, if you do not see warning signs on your dashboard, you must have the sensor checked by a certified mechanic. Check your tire pressure with a Tire Pressure Gauge.
2. TPMS Warning Light Illuminates
The ECU or PCM, which receives all the sensors’ information, triggers a warning on your dashboard indicating that something is wrong with the sensors.
If a sensor, such as a tire pressure sensor, is not operating by the standard, the ECU illuminates the TPMS light.
Consult a mechanic to diagnose the real reason for the TPMS symbol. You may also receive the message “Tire pressure sensor fault” on your dashboard.
3. Incorrect Warnings
If the tire pressure sensor is not functioning properly, you may receive improper warnings on the DIC. The sensor could indicate that you have a flat tire, even if there is nothing wrong with the tire. It may also indicate low tire pressure even if you have recently inflated the tires to the optimum pressure. However, these warnings should not be taken lightly as they may cause future problems.
Tire Pressure Sensor Location
The tire pressure sensor is located inside your car’s tires, attached to the inner part of the rim, the opposite side of the tire valve. You have one tire pressure sensor per wheel.
You can easily find it by removing the tire from the rim. It looks like a small cylinder.
How to tell which TPMS sensor is bad?
The easiest way to find out which TPMS sensor has gone bad is to read the trouble codes with an OBD2 Scanner.
If your car has a display of each wheel’s tire pressure on the dashboard, you can also check there if some pressure is irrelevant.
In most cars you need a diagnostic scan tool that can not only read codes from the TPMS system and not just the ECU. To find a scanner to do it, you can either check our article: Best OBD2 Scanners, or go to a mechanic workshop to do it for you.
What is a Tire Pressure Sensor?
The tire pressure sensor plays an important role in ensuring that your vehicle remains in perfect condition at all times. It calculates the air pressure in your car’s tires and alerts you if the air pressure is insufficient.
The tire pressure sensor contains batteries that are not replaceable, and after some years, they will run out of battery power, requiring you to replace the entire sensor. This is the most common reason why you need to replace them.
You can expect the batteries in a tire pressure sensor to last for 5-10 years at least, depending on the brand.
Tire Pressure Sensor Replacement Cost
The average tire pressure sensor replacement cost ranges from $40 to $100 per sensor, which means you can expect to pay between $160 and $500 to replace all four. The sensor itself typically costs $30 to $70, while labor runs about $10 to $30 per tire, depending on your location and shop rates.
Before replacing your tire pressure sensors, take the time to compare qualified mechanics in your area. While it may be tempting to choose the cheapest option, inexperienced or uncertified mechanics can make costly mistakes that lead to further issues down the road. It’s always best to have this job handled by a certified technician who understands your car’s TPMS system.
After replacing the sensors, don’t forget to reset the TPMS light to ensure the system recognizes the new components.
Keep in mind that sensor prices can vary based on several factors. The cost depends on your vehicle’s make, model, and year, as well as the type of sensor required. Older vehicles may have harder-to-find parts that cost more, while newer models often use more affordable or widely available sensors. However, this isn’t always the case; imported parts tend to be more expensive than locally produced ones.
Finally, remember that each tire has its own sensor. If multiple sensors fail at once, your total cost can rise quickly. For instance, replacing two or three faulty sensors can easily push the total close to $1,000, especially on higher-end or imported vehicles.
FAQs
Most tire pressure sensors last about 5 to 10 years or around 60,000 to 100,000 miles, depending on driving conditions and temperature exposure. It’s actually quite rare for a tire pressure sensor to go bad.
Yes, a faulty sensor often keeps the TPMS warning light on even when your tires are properly inflated. A diagnostic scan with an OBD2 scanner can confirm which sensor failed.
Yes, you can replace a single bad sensor. However, if the others are the same age, it might be more efficient to replace all of them to avoid future issues and the need to repeat the same procedure. But they can be pretty expensive, so it might be worth replacing just one.
Yes, you can still drive, but it’s not recommended for long periods. Without an accurate sensor, you won’t know if your tires are underinflated, which can lead to poor handling or tire damage.
Conclusion
A bad tire pressure sensor might seem like a minor issue, but it can affect both your safety and your car’s performance. If your TPMS light stays on, your readings seem inaccurate, or you keep getting false alerts, it’s best to have the system checked right away.
Replacing a faulty sensor not only restores accurate tire monitoring but also helps prevent tire damage and improves fuel efficiency. Staying on top of TPMS issues keeps your ride smoother, safer, and worry-free.
My Volkswagen Jetta’s ‘Low tire pressure or System Failure’ light is on. I filled my tires up with air, but the light stayed on for another 50+ miles. Then, when I started my car a few days later, it was as if the battery was drained and dying whilst I tried to turn my car’s ignition on. It was going in and out and having trouble turning over and starting. Each time I turn my car on it is getting worse. I was wondering if needing a TPMS replacement could be causing this. Please let me know your thoughts if you see this, thanks.
I have a 2005 infiniti G35X. Do tire pressure sensors ever come loose inside the tire/wheel? I have a definite pop over small and medium tar strips in the road.
excellent page with good information. thank you