While on the road, the importance of safety should never be underestimated.
Statistics show that the number of people killed in accidents annually is more than the number of people dying from various diseases. The fact is that, often, most car problems arise at home.
You start your car while going to work, and all the usual indicators light up. However, once the vehicle starts moving, most of these turn off and even if some remain on, you usually do not take much notice.
The tire pressure light or TPMS light is one such indicator that people often choose to ignore. One of the common reasons for this is that many people do not know what these lights are meant for.
That is why we’ve written this guide, to help you learn about the tire light on car and what to do when it turns on. So, let’s get started!
Table of Contents
Understanding The Tire Pressure Monitoring System
If your tire pressure light has turned on, there is no need to panic. Before you go rushing to the nearest tire repair service, it can be helpful to find the problem (if any).
Vehicle manufacturers are adding more and more safety features to their cars, and the TPMS is one of the most crucial ones. Tire lights, or to use the proper term, the Tire Pressure Monitoring System (TPMS) uses sensors to indicate low tire pressure, which can create hazardous driving situations.
The TPMS light appears on the gauge cluster of the vehicle, like amber or yellow lights resembling the cross-section of a tire with an exclamation mark. In some cases, the letters TPMS may also appear on the gauge.
This tire pressure monitoring system works independently in each wheel, setting off the TPMS light when detecting low air pressure in any of the tires. It usually triggers such a warning when the air pressure is 25 percent lower than the recommended tire pressure.
You can measure the cold tire pressure when the tires have been sitting idle for at least three hours. If the tire pressure light turns on, it indicates that the pressure of one or more of the tires may be outside the recommended range. Thus, knowing about it well in advance can prevent treadwear and the possibility of tire failure.
How Is Tire Air Pressure Measured?
Tire air pressure is measured in PSI, which means pounds per square inch. In other words, it is the amount of force applied in pounds to each square inch of the tire surface.
A tire pressure gauge shows the amount of pressure in kilopascals or kPa, which is the metric conversion of PSI. Generally, the air tire pressure is indicated in both units of measurement, so make sure to take a look at the PSI reading to prevent over inflating the tires.
The optimal performance and safety benefits of tires are only available within a specific air pressure range. Hence, the tire pressure light generally turns on before the problem becomes visible to the naked eye.
Problems With Over And Underinflation
Both over and underinflation are not good for the tires of your vehicle and can cause several problems.
Overinflation can cause decreased traction, reduce the impact absorption ability, and result in premature wear. The tire tread center will also have visible signs of damage in the case of overinflated tires.
On the flip side, underinflation can cause a sluggish tire response, heat buildup, reduced efficiency in fuel consumption, and overloading of tires. In such cases, you can see premature tire wear on the sides of the tread edges.
The Importance Of Maintaining Proper Tire Pressure
The tire pressure should always be set correctly to ensure optimal gas mileage and the best driving experience. Some of the benefits that a proper tire pressure provides include:
Slower Wearing Of The Tire Tread
Having proper air pressure in the tires will ensure that the tires last longer and do not require frequent replacements. When the pressure in the tires is low, the level of contact between them and the road will be much greater, increasing the chances of damage.
It is generally recommended not to drive with uninflated tires on any surface, including sand, snow, or gravel.
Longer Lasting Wheels
Overinflated tires can cause the vehicle to feel uncomfortable and rigid while driving. Similarly, high pressure can cause the tires to wear more quickly due to the greater amount of heat and friction produced.
Long story short, prematurely worn down tires can often result in flat tires, tread erosion, or tire blowouts.
Lesser Rolling Resistance
Tires with the right amount of air pressure have a lower level of rolling resistance. A lower rolling resistance will ensure that you get better mileage with the same amount of gas in the tank.
Better Protection Against Moisture
Proper air pressure in the tires will ensure that the vehicle maintains better control even in wet conditions. Hence, the chances of losing traction on wet surfaces goes down, which is essential for ensuring safety and preventing accidents.
Types Of TPMS Systems
Generally, there are two types of TPMS sensors onboard cars:
Direct TPMS
Direct TPMS sensors are present on the wheels of the vehicle and send a signal to the digital receiver when the pressure is low. All vehicles that have been manufactured in recent years come with this type of tire pressure light.
However, with this type of TPMS, the risk of damage during tire servicing or while traveling over harsh terrain, as well as wear and tear, is greater. Alternatively, the sensors may be placed in the tire valves, instead of being directly positioned on the tires. This placement offers better protection to the sensors, ensuring they last a bit longer.
Indirect TPMS
In the case of indirect TPMS, the sensors are present on the anti-lock brakes and determine whether the rotation speed of the tires is adequate. This type of sensor is more durable than Direct TPMS but only indicates that a single tire is deficient in air pressure.
In case all the tires are losing air pressure simultaneously, this system will not be able to detect it. However, more sophisticated TPMS systems can even display the real-time air pressure present in each tire and indicate which tire is out of the pressure range.
Common Causes Of Low Tire Pressure
We’ve listed some of the common causes that can trigger the low tire pressure light.
Ambient Temperature Change
The most frequent and common cause is the change in ambient temperature, especially in cold climates. During the day, when the temperature is higher, the tires have an adequate amount of air for driving. As the day draws to a close and the temperature starts falling, the air pressure existing in the tires also decreases.
Since the air density varies with the changes in temperature, the tire pressure light may turn on as the tire pressure sensors are affected by the cooler temperature.
Recent Tire Change
In case the tire position on any wheel was altered, you may need to reset the tire sensors. For this purpose, drive the vehicle around for a few minutes, which will enable the tire to reset, depending upon the make and model of the vehicle.
If this does not reset the tire sensors, visit a garage or dealership for complete calibration.
Damaged Tire Pressure Sensor
It happens mostly in the case of direct TPMS sensors, whereby they may get damaged when the vehicle travels over bumps or during tire servicing. If those tires are damaged or filled with substances other than air or nitrogen (like flat repairing sealants), the sensor can also get destroyed.
Similarly, the onboard battery that generally lasts for around five to ten years can wear out over time. Such occurrences can cause the tire pressure light to turn on.
Faulty Wheel Speed Sensors
In the case of an indirect TPMS system, the wheel speed sensors might be damaged, causing the tire pressure light to turn on.
Low Air Pressure In Spare Tire
If the TPMS warning light turns on when you are using a spare tire, it might mean that the spare tire has low air pressure. Since you will be using the spare tire only for a short period, it is not an issue to be concerned about.
Steps To Take When The Tire Pressure Light Turns On
When The Light Turns On
When the tire pressure light turns on, you should first manually check the tire pressure, using a gauge. The pressure will likely be lower than the recommended range, and you will need to fill in the air till the pressure reaches the manufacturer’s specification.
You’ll find the correct pressure mentioned on the driver’s door jamb or in the owner’s manual. However, remember that the TPMS is not a replacement for routine tire pressure maintenance.
Also, if you have checked the tires for the correct air pressure and found no problems with that, one or more tires may have developed a leak. Additionally, it is possible that the TPMS system might be faulty and needs repairs.
TPMS Light Turns On Then Turns Off
Fluctuating temperatures can cause the tire pressure light to first turn on and then turn off if the tire pressure is near a level that may trigger an alert. It usually happens when the tire pressure decreases overnight with a fall in the ambient temperature.
Tires tend to lose about a pound of pressure for every ten-degree drop in temperature. That is why tire pressure generally drops during the winter months, prompting a tire pressure warning.
Subsequently, the light can turn off in the morning as the ambient temperature increases, followed by heat from the vehicle engine. In this case, also, you will need to check the tire pressure using a tire pressure gauge and fill the air. But you should know that tires warm up while driving which raises the pressure by about three PSI.
The TPMS Light Turns On And Stays On
You may face a situation where the tire pressure light turns on for about one minute to 90 seconds and does not turn off. If this happens, then that means that the TPMS system of your car is malfunctioning.
Take the vehicle to an automotive repair center for inspection and until the system is repaired, it cannot be used to determine the air pressure in the tires. Check all the tires manually to ensure that the air pressure is within the recommended range, in such a scenario.
How To Check The Tire Pressure
In case the tire pressure light turns on, you should first check the pressure of each tire.
Using A Pressure Gauge Or Visiting A Gas Station
You can check the tire pressure using a tire pressure gauge but if you do not have one, it is easily available at a reasonable price in most shops. Alternatively, you could visit the nearest gas or service station and get it checked there.
Refilling The Tires
As mentioned above, check the instruction manual or the driver’s inner door panel of the vehicle for the recommended pressure range. The PSI pressure does not have to be exactly the same as recommended but should be within the specified range.
If the pressure is low in all tires, that may have occurred due to a drastic drop in ambient temperature. Simply refill all the tires and drive the vehicle to reset the sensors.
Resetting The TPMS Light
Once you have filled up the required amount of air, the tire pressure light will need a few minutes before it resets. Also, drive for a few miles so that the car warms up and the pressure in the tires increases. What’s more, you may even need to reset the tire pressure warning light.
Performing A System Reset
Most vehicles have a simple procedure for resetting the tire pressure light and the process of resetting the system may be mentioned in the owner’s manual. There may either be a TPMS reset button in the car settings menu or the glove compartment, so follow these steps to reset the tire pressure light.
- Start the car without turning it on (put it on idle).
- Press and hold the TPMS reset button for 3 seconds.
- You will get a beep once the TPMS light turns off.
- Start the car and drive for about half an hour at a constant speed of 20 miles per hour.
- Once you’ve completed this procedure, the TPMS light will have successfully reset.
Repairing The TPMS System
Ensuring that the air pressure existing in each tire is adequate and within the limits prescribed by the manual will help you resolve the issue quickly. However, in case the TPMS light remains on, contact the dealership to get help. You can easily get the TPMS light repaired for free if the car is still under warranty.
Even if the warranty of the vehicle has expired, replacing the TPMS light is very simple and can be done at a reasonable price. Many local tire repair businesses can get the job done without you needing to break the bank.
Some Frequently Asked Questions
Is The Car Safe To Drive If The TPMS Warning Light Is On?
It is always recommended to get the air pressure in your car tires checked and fill them as soon as the TPMS warning light turns on. Ignoring it can lead to severe problems later on, not only for you but also for others on the road.
While you can drive the car even with the warning light on, you may lose some amount of control and face issues like increased tire wear or bumpier ride.
What Can You Do To Reduce TPMS Warnings?
You can easily reduce the chances of the tire pressure warning light coming on by performing basic maintenance regularly on the vehicle. Check the tire pressures once a week or while washing the car, and also have the sensors tested every four to six months. Additionally, replace and refurbish the wheels before the sensors give out.
Does A TPMS Replace Regular Pressure Checks?
A TPMS system helps you know whether any of the tires in your vehicle is deficient in air. However, that does not mean that it can replace regular tire pressure checks. For instance, the TPMS light may be set to light up below the pressure that is required for the vehicle to run properly.
In some cases, it might be faulty and may not transmit data accurately to the onboard computer. The system might also not be able to determine whether the air pressure is too low if all the tires are losing pressure at the same rate.
Do You Need To Replace The TPMS When You Get New Tires?
It is not mandatory to have the TPMS sensors replaced when getting new tires, but you should check them and ensure that they are still in excellent condition. A new TPMS system lasts for about ten years before the batteries give out. However, this period may be shorter for older vehicles.
Also, if you have an indirect TPMS system, the mechanic will need to reset the sensors manually.
Final Words
The TPMS system is a very useful tool and can help you determine whether your vehicle has sufficient air pressure present in its tires. It can also prevent future problems as well as guarantee safety while driving on the road.
Knowing how the system functions and the various causes of the light turning on can help you be prepared. However, solely relying on the TPMS system is not recommended, as the system can suffer from defects.
Regular checks of the air pressure in tires is still the most effective way of making sure that the tires are not low on air pressure.