Learn what a tire pressure sensor fault means, as well as its causes and possible fixes.
It’s a very common problem. You know, when you’re gleefully driving and then suddenly notice that the “Tire Pressure” warning light has come on.
You have an idea of what it entails but aren’t quite sure what caused it, how serious the underlying problem is, and how much it will cost to fix. Naturally, you came to AutoTribute for answers.
In this article, we provide everything you need to know about a tire pressure sensor fault, including its meaning, implications, and what you can do to correct it.
What is a Tire Pressure Sensor?
A tire-pressure monitoring system (TPMS) is an electronic system that continuously monitors the air pressure inside a vehicle’s tires using a computerized pressure sensor located in each tire. It alerts the driver when a tire becomes underinflated or even overinflated.
Considering that your tires provide the grip needed to bring your car or truck to a stop so that you don’t hit something, they are one of the most important safety components of any road-going vehicle.
Tire-pressure monitoring systems help ensure your tires have the proper air pressure to accomplish that task and are such an invaluable safety feature that they are mandatory on all vehicles in many countries around the world.
In addition to making your vehicle safer, they also help avoid poor fuel economy and increased tire wear due to underinflated tires.
Types Of Tire Pressure Sensors
There are two main types of tire pressure sensors: direct TPMS and indirect TPMS.
A direct TPMS uses sensors integrated into the tire valve to directly gather accurate pressure data, providing real-time information to alert drivers when the air pressure in their tires reaches a suboptimal level.
Indirect TPMS, on the other hand, monitors the speed of a wheel relative to the others using the ABS to approximate tire pressure. Underinflated tires have smaller circumferences than properly inflated tires and rotate faster, as a result.
Since an indirect TPMS system doesn’t provide real-time reporting, you may need to drive for a while before being alerted of a poorly pressurized tire.
Regardless of the type, all tire-pressure monitoring systems illuminate a light in the instrument cluster or on the dashboard to warn you when the pressure reading of a tire is lower than it should be.
Causes Of The Tire Pressure Sensor Fault
Many things can cause your tire pressure sensor light to go off; however, the most common causes are low tire pressure, a faulty tire pressure sensor, and forgetting to reset the TPMS after changing the wheels.
Let’s look at each one in more detail.
Low Tire Pressure
This shouldn’t come as a surprise. After all, detecting low air pressure in a tire is the primary reason why tire-pressure monitoring systems were created in the first place.
If you see the light turned on, there is a good chance that one or more of your tires is underinflated or overinflated. Don’t ignore it!
Faulty Pressure Sensors
It’s quite common for a faulty tire pressure sensor to also trigger TPMS warning flight. Not only are tire pressure sensors located in the tires, which tend to take a lot of abuse, but they are also powered by batteries that typically last 5-7 years and eventually die out.
Sometimes, the fault is caused by the sensors losing effective communication with the tire pressure control module. Other times, it’s due to damage sustained from elemental factors such as corrosion.
Most people don’t know that the TPMS needs to be reset every time a vehicle’s tires are replaced with a set that it has never been equipped with. Wheels and tires have different properties, so the sensors need to be recalibrated to ensure compatibility.
Needless to say, if the tire pressure sensor light turns on after a tire change, the sensors might need to be reprogrammed.
What Does Tire Pressure Sensor Fault Mean?
The TPMS warning light will often behave differently depending on the underlying problem. When it comes on and stays on, it usually means there is low air pressure in at least one of the tires.
Temperature changes can have a direct effect on the air pressure in a tire, causing the TPMS light to turn on and then off. This is prevalent during the nighttime, when ambient temperature drops, especially if tire pressure is near the level that triggers an alert.
The pressure sensor warning light should turn off as ambient temperature and pressure increases during the daytime and/or your vehicle heats up as it drives. If it stays on, check the pressure of all the tires and add air as needed.
Finally, if you notice that the light flashes for about a minute or two every time you start your vehicle and remains illuminated, it usually means the TPMS is defective in some way and needs to be inspected by a technician.
A faulty TPMS won’t be able to warn you of low tire pressure, placing you at a higher risk of an accident. You might also experience a drop in fuel efficiency and increased tire wear without realizing under-inflated tires are the cause.
How To Fix A Tire Pressure Sensor Fault
Fixing or correcting tire pressure sensors is fairly straightforward, though some problems may require more effort than others and sometimes even professional assistance.
The following are the most common fixes.
Check Tire Pressure
The first thing you should always do when the TPMS warning light turns on is to check the air pressure of all your tires. Oftentimes, the alert is triggered because at least one of the tires is underinflated or overinflated.
There is no need to pay a mechanic to do this — you can check tire pressure yourself by using a quality tire pressure gauge. If you’re looking for one, we recommend the AstroAI Digital Tire Pressure Gauge.
The correct tire pressure for your car or truck will depend on its make, model, and year. On newer vehicles, the figure can often be found on a sticker inside the driver’s door. Otherwise, crack open your owner’s manual to find it.
After inflating or deflating the affected tire(s) to the correct pressure level, it’s best practice to manually reset your TPMS to reacclimate it. Some vehicles have a reset button that you simply press, while others require the use of a diagnostic tool.
Of course, if a tire is underinflated because of a puncture, have it replaced immediately. Don’t be foolish to drive with a punctured tire.
Read Error Codes
If the TPMS light stays on even after correcting the air pressure in the problematic tire(s), use a diagnostic tool to read the TPMS system error codes and determine the underlying problem.
It may be due to a faulty tire pressure sensor, a communication error with a tire pressure sensor, or another issue. Either way, you won’t be able to know without reading the trouble codes on your vehicle.
Check The Battery
If your vehicle’s tire pressure sensors use battery power, ensure the batteries are not dead. A pressure sensor with a dead battery won’t be able to alert you when there is a problem with your tire pressure or the TPMS system.
Don’t wait until the battery expires. It’s a smart idea to install a new one every five years.
Some sensors have their battery built into them, so you may have to replace the entire sensor unit.
Reprogram The Sensors
Sometimes, the fault is caused by the tire pressure sensors losing communication with the TPMS control module. If something like this happens, you will need to reprogram all the sensors to reacclimate them to the control module.
A TPMS reset tool is required for this repair.
Replace Faulty Sensor
If you have exhausted all your options but the TPMS light is still on, one or several of your tire pressure sensors is probably faulty. Check the trouble codes of your scanner tool to determine the problematic sensor, and replace it.
Don’t forget to reprogram all the sensors after installing a new one.
Tire Pressure Sensor Fault FAQS
We don’t fault you for having more questions about tire pressure sensors. Keep reading for answers to several other popular questions on the subject.
Is It Safe To Drive With The TPMS Light on?
No. When the TPMS light is on, it usually indicates that your vehicle is compromised in its safety and is not safe to drive.
Oftentimes, it means one or more of your tires is underinflated or the TPMS is not functioning properly. Both cases can cause the tires to wear at an accelerated rate, fail prematurely, and even sustain a blowout, potentially leading to an accident.
So, no, it’s not safe to drive with the TPMS light on.
How Much Does It Cost To Replace Tire Pressure Sensors?
Replacing a faulty TPMS sensor typically costs between $50 and $100 each. This price includes labor costs but not taxes, fees, or other expenses pertaining to the particular make and model of your vehicle.
It’s more expensive to replace a direct TPMS than an indirect TPMS.
Where Is The Tire Pressure Sensor Located?
Tire pressure sensors are typically located inside the wheels. They are attached to the inner part of the rim, often on the opposite side of the tire valve.
Each of your vehicle’s wheels only has one sensor, and it can be found very easily by removing the tire from the rim.
Do Run-Flat Tires Have Tire Pressure Sensors?
Run-flat tires have a design that lets you continue driving even after a tire gets a puncture and loses some or all of its air pressure. They feature an interior support ring or reinforced sidewalls that provide structure and support, allowing them to operate at reduced speeds.
Because of this, drivers of vehicles with run-flat tires can often drive without feeling the effects of a puncture or reduced air pressure in a tire. This makes a tire-pressure monitoring system an invaluable tool to have.
So, yes, run-flat tires also need tire pressure sensors. Without them, it would be hard to know when they have low air pressure.
Is It Illegal To Not Have TPMS?
In some places such as the United States, EU, Japan, and South Korea, tire pressure monitoring sensors are mandatory on all vehicles. Countries such as Canada, on the other hand, have no such requirement.
Many older vehicles lack a tire pressure measurement system of any kind; however, they can be retrofitted with aftermarket TPMS systems.
Even if your jurisdiction doesn’t require your vehicle to have a TPMS, you should play it safe by having one installed. Knowing how much air pressure you have in your tires will keep you safer on the road and maximize the performance and lifespan of the tires.
Tire pressure sensors play an important role in keeping you safe on the road and maximizing the performance of your tires. They help alert you when your tires are underinflated or overinflated so that you can take the correct action to get their air pressure back to normal.
Many things can cause your tire pressure sensor light to go off; however, the biggest culprits are a faulty tire pressure sensor and, of course, low tire pressure.
When the light appears on your dashboard, your first step is to check the pressure level of all of the tires using a tire pressure gauge, determine the underlying cause of the pressure loss, and get the pressure back to the recommended level.
Sometimes, the solution to the problem is as easy as pumping more air into the affected tire; other times, the problem could be so serious as to require professional assistance. Take your vehicle to a trusted technician if the latter is the case.
Now that you know what a tire pressure sensor fault is all about, how about learning about other common car issues? We have articles about the symptoms of metal shavings in oil, why a car might shake when accelerating, and symptoms of bad spark plugs.