TPMS Light Is On: What Does It Mean? What To Do?

You need to keep all your tires properly inflated for the best overall performance. It pays to frequently check tire pressure yourself using a reliable pressure gauge. Besides that manual way, the car’s TPMS will also do the same using TPMS sensors. When it detects a problem (like over- or under-inflation) it will notify you by triggering the TPMS light.

What Does It Mean When TPMS Light Comes On?

TPMS Sensor.
TPMS Sensor. Credit: https://en.wikipedia.org/wiki

While under-inflation and over-inflation are the main triggers of the TPMS light, it can come on for other reasons. Switching tire sizes, rotating tires or changing tire pressure are just a few examples. Generally, you will know what the problem is based on how the light came on. Here’s a brief guide:

TPMS Light Came On While Driving

If you are driving and then you see the TPMS light on then it means that one or more tires is severely underinflated. In case you can’t pinpoint it by observation go ahead and use a pressure gauge to check your tires. If the pressure is low for any reason other than a leak you can simply inflate it to the recommended level and the drive on.

If there’s a leak you may have to replace the tire with a spare as you plan to get the damaged one serviced or replaced. Note that the light will go away once the problem is fixed and you have driven for a significant distance, like 10 miles.

TPMS Light Keeps Coming On And Off

It’s possible for the TPMS light to come on and then go off shortly after, only to come on again. If it keeps doing that then it means the tire pressure has been affected by external temperature.

TPMS
TPMS icon.
Credit:https://en.wikipedia.org/wiki

Usually, when the temperature drops so does air pressure. The reduction in pressure can trigger the TPMS light. You might see this happening in the morning after the car has sat overnight in a cool temperature.

Conversely, when the temperature rises air pressure increases. That increase makes the TMPS light to go away. It can happen a few minutes after you’ve driven the car, or when the sun comes out.

TPMS Light Flashes When You Start The Car

If, when you start your car, the light flashes for about 60 to 90 seconds and stays on it means that the TPMS system has malfunctioned. In that case, the problem is not with the tires but rather the monitoring system itself.

Unless you are an auto mechanic, you need to visit the shop or call your mechanic to diagnose and possibly repair the problem. You don’t want to drive with a faulty TPMS because you need to know the state of your tires for safe driving.

What Is TPMS Sensor/Tire Pressure Sensor?

I’ve been going on and on about the TPMS and its ability to monitor tire pressure. You’re probably wondering, how exactly does it do that? Well, it uses sensors.

A TPMS sensor picks up information from your vehicle’s tire and relays it to the TPMS. If there’s a pressure-related problem the system will report it to you via the dashboard light. From there you can know whether it’s a case of an underinflated tire or a leaky one.

TPMS light
TPMS system failure icon.
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There are two types of TPMS sensors. The first type is usually located either on the rim or the tire pressure valve. A pressure monitoring system that uses such sensors is called a direct TPMS. While it works fine in monitoring pressure, a direct TPMS is prone to malfunction because of exposure to bad weather conditions. It’s the most common TPMS in the United States.

The second type of TPMS sensor is located either on the ABS brakes, the speed sensors or both. A system using these sensors is known as an indirect TPMS. Although it’s more durable, an indirect TPMS may suffer from accuracy issues. European-made cars use it more than the direct type.

Regardless of the type you use, a TPMS will bring the dashboard light on when there’s an issue. But how can you turn that light off? Hop over to the next section for that.

How Do I Get The TPMS Light To Go Off?

Want to reset the TPMS light? There are several ways of doing that:

1. Correct Inflation

First things first, start by ensuring that all your tires have the right pressure. Manufacturers usually indicate the recommended pressure on the tire. Use a pressure gauge to check each tire and ensure that its PSI reading is within the recommended range.

Re-inflate any tire whose pressure is severely low and then drive the car for several minutes at 15mph. it will calibrate the TPMS sensors manually and reset the TPMS light.

While that’s a reliable (and rather obvious) method of doing it, at times it just doesn’t work. In that case, try any other method below or a combination of two.

2. Drive 10 miles at 50mph

If the 15mph drive didn’t reset the light increase the speed to 50mph and drive at least 10 miles. Be sure to use the cruise control to keep a constant speed. Once the 10 miles is over turn off the car and then start it again. The light should automatically go off.

So, why 50mph? Because there are some TPMS sensors that respond better at higher speeds.

3. Deflate then re-inflate the tires

If steps 1 and 2 didn’t turn the TPMS light off try deflating the tires to zero and then re-inflating them to the recommended PSI each. After that do 15mph for several minutes for the light to reset.

4. Use the reset button

At times, even after getting the PSI right, the TPMS light just fails to reset. In that case, you can use your car’s reset button to do that. Without starting the car, insert the key to the ignition and turn it to the ‘ON’ mode.

Now, press and hold the TPMS reset button until the TPMS light blinks three times. Release the button, start the car and let the engine run for about 20 minutes and then turn it off. It should automatically recalibrate each TPMS sensor. The next time you start the car the TPMS light will have turned off.

Do you know where the TPMS reset button is located in your car? More often than not you will find it either under the wheel (like in Toyota cars) or on the left side of the wheel (like Honda models that are older than 2016). Most VW models have the button near the gear shift or inside the glove box while Mini cars have it in the front cabin where the emergency brake handle is.

5. Disconnect then reconnect the car battery

At times the TMPS light can persist simply because of a glitch in the car’s on-board computer. So if you’ve tried the 4 steps above without success try resetting the on-board computer. It’s as easy as disconnecting and reconnecting the car’s battery.

6. Use a TPMS reset tool

There are two types of tools that you can use to reset the TPMS light. The first type includes dedicated TPMS reset tools like the VXDAS EL-50448 and ATEQ QuickSet TPMS Reset Tool. These are designed for doing that and nothing else.

Secondly, you can use an OBD scanner. Some OBD2 scan tools come with various functions, including the ability to reset the TPMS light. Some good OBD scanners with TPMS reset function includes the Autel MP808TS and Launch CRP808.

Whichever type of tool you pick, it will allow you to turn the TPMS light off with just one click of a button. Some even enable you to relearn each TPMS sensor.

Read more: Honest Review of the Best TPMS Reset Tools 2019

Tire Pressure Light Still On After Filling Tires, What To Do Now?

What if the TPMS light persists to be on yet the tire pressure is correct and you’ve tried all the methods above? In that case, it’s more likely that the TPMS sensor is faulty. Sometimes the tire can be absolutely fine, but a problem with the TPMS sensor triggers the TPMS light anyway.

Such problems include a dead battery in the TPMS sensor, wrongly calibrated air pressure gauge or a damaged TPMS sensor. In the case of the latter, you may have to take the car to the shop for the TPMS sensor to be replaced (depending on the extent of the damage). There are many things that can damage a TPMS sensor. They include:

  • Wear and tear from exposure harsh weather conditions
  • Damage during normal tire service
  • Damage caused by tire rotation
  • Damage during brake repair or service
  • Damage during tire replacement
  • Damage during oil or filter change
  • Damage during a CV boot/axle replacement

How Much Does It Cost To Replace TPMS Sensor?

There’s no one-answer-fits-all here. The amount of money you will spend on replacing TPMS sensors depends on the rates of your auto shop or dealership. However, a ballpark amount that you can work with ranges from $150 to $260 for each wheel. So if you own a four-wheeler you’ll be looking at any amount between $600 and $1,040 (labor inclusive).

Sounds pricy? There’s an alternative. Rather than depending on the mechanic to buy the sensors and do the replacement, you can buy them yourself and only hire a technician to do the replacement.

TPMS sensors can be as cheap as $19 or as expensive as $119. Needless to say, it’s not always a good idea to go with cheap stuff, especially when you are buying car parts. You need to be careful though because the TPMS sensors you buy SHOULD be compatible with your car’s on-board computer.

As mentioned already, if the TPMS fault was not caused by a damaged TPMS sensor then it’s either a dead battery, wrongly calibrated air pressure gauge or similar problem. To correct it you will have to rest the TPMS sensor.

How Do You Reset The Tire Pressure Sensor?

Resetting the tire pressure sensor will make it function properly again. Remember I mentioned that one way of resetting a TPMS sensor is by disconnecting and reconnecting the car battery. That resets the on-board computer and may also reset a faulty TPMS sensor.

There are other ways of correcting TPMS sensor faults and resetting the sensor:

1. Check battery

I’m talking about the sensor’s battery, not the car battery. Each TPMS sensor is powered by a battery, so make sure it’s not dead. After about 5 to 7 years the battery of a TPMS sensor will run dry and require replacement. If the sensor has a built-in battery you will have the replace the whole unit.

2. Recalibrate transponders 

Tires usually have transponders that communicate with the sensor. At times the sensor may fail to learn the new position of the transponder when the wheel is rotated. That calls for you to relearn the TPMS sensor. You can find the relearning procedure either on your TPMS manual or on various online platforms that deal with vehicle repair.

3. Use a scan tool

Remember the OBD scan tools that I talked about briefly when discussing how to turn the TPMS light off? Yeah, those too can reset a TPMS sensor. Most of them come with built-in instructions on how to do that.

Can You Remove TPMS Sensor Altogether?

Looking at the cost of replacing a TPMS sensor or the (somewhat) tedious process of resetting it, some people might be tempted to just chuck it out. Well, that’s possible, but keep in mind that doing that is dangerous and could be criminal.

According to NHTSA’s law, any car that’s newer than 2008 SHOULD be equipped with a TPMS. In essence, removing the device is breaking the law.

Besides, you might find it hard to detect problems related to the tire pressure. Some problems, like an undetected leaky tire, can make it hard for you to control the vehicle. And if you can’t control it then you are at risk of getting an accident.

Is It Safe to Drive with TPMS Light On? (Driving With Low Tire Pressure)

So, it’s not okay to remove a TPMS sensor. But can you drive with the light on? Again, yes you can, but it’s not a good idea. When the light is on more often than not it means that at least one tire is underinflated.

Besides wearing out prematurely, it can blow out and cause you to lose control of the car. The best thing is to try and reset the TPMS light as quickly as possible.

Is Regular Tire Pressure Check Necessary When You Have TPMS?

Absolutely! Knowing what a TPMS light means and how to react to it is very important. But it doesn’t replace the good old method of checking tire pressure.

Why? Because a TPMS has its limitations. For example, TPMSs are usually set to trigger the light when the tire pressure goes below a certain minimum. However, that minimum may not be enough to support a load that you want to carry in your car.

Additionally, the sensor may be inaccurate. Or it may fail to detect low pressure when all the tires are losing pressure at the same rate. Such challenges make it necessary to keep checking tire pressure manually. So don’t throw away that pressure gauge just yet.

Tim MillerFounderOBD Advisor

I’m Tim Miller from Denver, Colorado. I’m the founder of obdadvisor.com, an automotive blog about "Diagnostic Tools and Auto Repair". My fan page is facebook.com/autozikcom. I've been working as an automotive mechanic and blogger for over 10 years writing articles to share my experiences and expertise.

Web: https://www.obdadvisor.comEmail: [email protected]
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