What is TPMS?
The purpose of the tire pressure monitoring system (TPMS) in your vehicle is to warn you that at least one or more tires are significantly underinflated, potentially leading to unsafe driving conditions.
The TPMS low tire pressure indicator is a yellow icon that illuminates on the dashboard instrument panel in the shape of a tire cross-section (resembling a horseshoe) with an exclamation point.
This indicator light in your vehicle has a history. It’s a story based on years of uncertainty about proper tire pressures and many serious car accidents that could have been avoided if drivers had known their air pressure was low.
Even now it is estimated that a significant number of vehicles hit the road with underinflated tires every day. However, proper tire maintenance with the help of a TPMS can and can help prevent many serious accidents.
Before this indicator light became commonplace, knowing if your air pressure was unsafe meant getting out, crouching, and using a tire gauge. With a few exceptions, this was the only pressure testing tool ordinary consumers had.
In response to an increase in accidents due to underinflated tires, the US government passed the Transportation Recall Improvement, Accountability, and Documentation Act (TREAD). One of the results of this legislation is that most vehicles sold in the US since 2007 include a tire pressure monitoring system.
Not all TPMS work the same way. Illuminating the low tire pressure indicator is the final step in the process of an indirect TPMS or a direct TPMS.
What are the Types of TPMS And How Does it Work?
There are two different types of systems being used today: Direct TPMS and Indirect TPMS.
1. Direct TPMs
It uses an in-wheel sensor to measure the air pressure in each tire. When the air pressure drops 25% below the manufacturer’s recommended value, the sensor transmits this information to your car’s computer system and triggers the indicator light on your dashboard.
Direct TPMS uses pressure monitoring sensors within each tire that monitor specific pressure levels – not just wheel revolution data from the anti-lock brake system.
Sensors in a direct TPMS may even provide tire temperature readings. The direct tire pressure monitoring system sends all of this data to a centralized control module where it’s analyzed, interpreted, and, if tire pressure is lower than it should be, transmitted directly to your dashboard where the indicator light illuminates.
A direct tire pressure monitor usually sends all of this data wirelessly. Each sensor has a unique serial number. This is how the system not only distinguishes between itself and systems on other vehicles but also among pressure readings for each individual tire.
Many manufacturers use proprietary technology for these highly specialized systems, so replacing a TPMS in a way that’s consistent and compatible with your vehicle will require an experienced, knowledgeable technician.
Advantages Of Direct TPMS
- Deliver actual tire pressure readings from inside the tire
- Not prone to inaccuracies because of tire rotations or tire replacements
- Simple resynchronization after tire rotation or tire replacements
- Batteries inside the sensors usually last for about a decade.
- May be included in a vehicle’s spare tire
Disadvantages Of Direct TPMS
- More expensive overall than an indirect TPMS
- Though simple, resynchronization may require costly tools.
- Battery rarely serviceable; if the battery is drained, the whole sensor must be changed.
- Proprietary systems make installation, service, and replacement confusing for consumers and auto shops.
- Sensors are susceptible to damage during mounting/demounting
2. Indirect TPMS
It works with your car’s anti-lock braking system (ABS) wheel speed sensors. When the tire pressure is low, it will roll at a different wheel speed than the other tires. This information is recognized by your car’s computer system, which triggers the dashboard indicator light.
An indirect TPMS is usually based on wheel speed sensors that the anti-lock braking system uses. These sensors measure the rate of rotation each wheel is making and can be used by onboard computer systems to compare them with each other and with other vehicle operating data such as speed.
Based on the rate of rotation of each wheel, the computer can interpret the relative size of your vehicle’s tires. If a wheel spins faster than expected, the computer calculates that the tire is underinflated and alerts the driver accordingly.
An indirect tire pressure monitoring system does not measure tire pressure. It doesn’t electronically process the same type of measurement you might see with a tire gauge. Instead, an indirect tire pressure monitor simply measures how fast your tires are spinning and sends signals to the computer that actuate the indicator light if something is wrong with the rotation.
Advantages Of Indirect TPMS
The TPMS eliminates guesswork by notifying you if a vehicle is low on air or flat. This knowledge can not only help prevent accidents but can also help you improve your gas mileage. Your TPMS can also warn you about existing or impending problems with your vehicle.
- Relatively inexpensive compared to a direct TPMS
- Requires less programming/maintenance over the years than a direct TPMS
- Less overall installation maintenance than its direct counterpart
Disadvantages Of indirect TPMS
- It May become inaccurate if you purchase a bigger or smaller tire
- It Maybe unreliable when tires are unevenly worn
- Must be reset after properly inflating every tire
- Must be reset after routine tire rotation
What does TPMS mean?
It stands for Tire Pressure Monitoring System, and it uses tire pressure sensors to track the air pressure of your tire. This system will turn the light on, or the TPMS lights flash when it senses that one or more tires aren’t at the recommended pressure.
Is it safe to drive with TPMS light on?
It’s not safe to drive around with your TPMS light illuminated. Without a tire inspection, there’s no way of knowing how quickly air is leaving your tire, or for how long it has been over or underinflated. The best course of action is to use a tire pressure gauge to check the current inflation level of each tire.
How much does it cost to replace a TPMS sensor?
In the event TPMS sensors need to be replaced, the cost can range from approximately $50-$100 each depending on vehicle type.
How do you fix TPMS?
Press the TPMS reset button and hold it until the light blinks three times, then release it. Start the car and let it run for 20 minutes to reset the sensor. You’ll usually find the tire pressure monitor reset button beneath the steering wheel. Check your user’s manual if you’re having trouble locating it.
What is the difference between TPMS and low tire pressure?
How do I know if my car has TPMS?
In the U.S., if you purchased a car or light duty vehicle under 10,000 lbs, manufactured after September 1, 2007, you have TPMS. If your model was manufactured after October 5, 2005, you may have TPMS. Also, prior to the legislation, some higher-end vehicles also came equipped with TPMS as a premium option.
Where is TPMS sensor located?
Where is the tire pressure sensor located? It is inside the tire attached to the inner part of the rim. If you remove the tire from the rim, you’ll see a small cylinder, which is the tire pressure sensor.
Why TPMS light on but tires are fine?
When air pressure on one or more of your tires falls below 25%, the TPMS light comes on. Before you inflate the tires thinking that the air pressure is incorrect, be sure to check for yourself.
How long can you drive with TPMS light on?
If the tire pressure is nominal and there are no leaks, but the TPMS warning light is still on, you could attempt driving for at least 10 minutes at over 30mph to warm the car up and wait for the warning light to turn off. You could also try resetting the TPMS warning light to disable the warning.
What causes TPMS light to come on?
It’s a tool that can help alert you when pressure is low, but a tire may drop below proper inflation long before the TPMS warning light comes on. The TPMS light comes on when the tire pressure gets too low or too high.
Can I install TPMS sensors yourself?
Installing cap-based tire pressure sensors is straightforward. Even if you have no experience working on your car, you won’t have trouble. In most cases, all you do is screw on the sensors in place of the valve stem caps. Avoid cross-threading the sensors because you need a tight seal for the system to work correctly.
Do I have to replace all 4 TPMS sensors?
While most sensors do not run 24/7 – in this manner, they work on a battery-saving mode, they still have a lifespan. Usually, that span is between 5 to 10 years. Once the battery runs out, depending on the vehicle’s system, you might need to change the entire TPMS system or the individual sensors.
Can I replace just one TPMS sensor?
If one of your TPMS sensors fails and needs replacement, you can replace it individually. However, if the failure was caused by a dead sensor battery, it’s likely that the other sensors are close to failing as well.
How much is a tire sensor?
Replacement tire sensors vary in price depending on your vehicle and can be found from many sources, from Amazon to Advance Auto Parts to Tire Rack—or at your local tire store. Expect to pay at least $100 for a set of four, and they need to be replaced at a repair facility or tire store.
Can a TPMS be fixed?
In short, you can just replace one TPMS Sensor. However, just make sure to retrain the new sensor with a TPMS Relearn Tool.
Who can install TPMS sensors?
Your local technician can help you decide whether to replace TPMS sensors based on the life expectancy of your new tires, and we’ll be here to replace your sensors when the time is right.
Is TPMS required?
In the United States, TPMS is mandatory for all vehicles produced after September 2007. In the European Union, TPMS is mandatory for all new passenger vehicles released after November 1, 2012.
Can cold weather affect TPMS?
The TPMS Light is Potentially Triggered by Winter Weather. When the weather is cold, the pressure in a vehicle’s tires may naturally fall. The TPMS light can be easily activated because of this, flickering on automatically the moment the tire pressure falls below its 25% threshold.
What is TPMS in my Honda?
Legendary reliability, comfort, and technology are all part of the show, but lately, your tire pressure light has come on. Your Honda vehicle’s tire pressure monitoring system (TPMS) is a sophisticated piece of equipment that’s there to alert you to an issue before a bigger problem arises.
How do you test TPMS?
Where is my TPMS reset button?
In most vehicles, the TPMS reset button is found beneath the steering wheel. After changing the tires on your vehicle, the TPMS needs to be electronically reset in order to clear the error code. To do this, hold in the TPMS reset button until the tire pressure light blinks three times, then release the button.
How often do you need to replace TPMS?
TPMS sensors are designed to last for many years – 5-10 years is a likely lifespan. Given their cost, most drivers will be inclined to replace TPMS sensors on an “as needed” basis – in other words, only once their batteries have expired, or other TPMS components have failed.
How do you fix a TPMS sensor without replacing it?
How long does it take to fix a tire sensor?
Replacing a tire pressure sensor can take anywhere between 10 minutes to an hour. It’s recommended to have your tire sensor replaced by a professional, especially if you’re not familiar with the equipment.
Can I remove my TPMS sensors?
Unfortunately, there is no way for you to remove the TPMS sensor without removing the tire. That’s because the sensor is located inside the tire and is mounted on the rim of the wheels. As such, conventional wisdom would say that you have to remove the tire for you to be able to reach the sensor.
How does TPMS know which tire is which?
Indirect TPMS works with your car’s Antilock Braking System’s (ABS) wheel speed sensors. If a tire’s pressure is low, it will roll at a different wheel speed than the other tires. This information is detected by your car’s computer system, which triggers the dashboard indicator light.