Home Diagnosis and TroubleshootingBraking System Why Is My ABS Light On – Why Is This The Case?

Why Is My ABS Light On – Why Is This The Case?

by Jordan Harris
Why Is My ABS Light On

Have you noticed the ABS light on the dash and you keep asking yourself why is my ABS light on? Well, if that is the case and you are in this situation, then you are at the right place because there will be a lot to cover on this topic.

Having a problem like this is not an easy thing and you should be worried. Namely, this ABS system is one of the most essential systems in your car. Why I’m saying this? Well, because it is true. This system helps your car to come to a stop in some tight situations.

So, if you don’t have a properly working ABS system, you risk getting yourself hurt or possibly hurting somebody else. Although many people would say that you can live without it, that isn’t the case in reality. You might not need it in 99% of the cases, but that 1% of when you will need it, you will regret not fixing it on time. That’s why you need to learn everything about it and how to fix this system.

First, we will cover the ABS meaning and we will dive into how this system works. Then we will cover the antilock braking system light and why it turns on. After this, we will dive into car diagnostics and learn more about how diagnostics are done, and then we will answer the question of why is my ABS light on? By listing all the common causes.

Lastly, we will learn how to diagnose and fix the problem. So, if you want to learn more, follow along till the end.

ABS Meaning

Now before we dive into more complex topics like the anti-lock braking system light and why is my ABS light on, let’s first learn the basics of the ABS system and that is the ABS meaning. What this ABS means and how does it work in reality? Let’s elaborate.

The ABS abbreviation is referring to the anti-lock braking system. This system is one of the most essential systems in our cars when it comes to safety along with traction control.

This system prevents the tires from skidding and locking up and causing a situation where you slide while you apply the foot on the brakes. But how does this system works in reality?

Well, this system is working with the help of the speed sensors that are located on each of the wheels. These sensors are measuring the rotations of the wheel and basically observe the speed. When they notice abnormalities such as situations when you slam on the brakes. These sensors will get this input and then will send this data to the ABS control module.

Then this module will activate the ABS pump and will send intermittently very small pulses of hydraulic fluid into the brakes. This will result in the brakes pressing and releasing the rotor a number of times in a fraction of a second.

This will result in a much better stopping power. The wheel will not lock up in this situation and your tire will not get damaged and get flat spots.

Not to mention the safety aspect, the stopping distance with ABS on and ABS off is really something that is not comparable. ABS is the way to go. But why is my ABS light on? Let’s see next.

Antilock Braking System Light

Now before we learn why is my ABS light on, let’s first see what is this light in the first place and why it is so important to you as a car owner?

The ABS light on should not scare you only in one case. And that is when you slam on the brakes really hard and try to come to a stop. In this case, the light will flash intermittently until the car comes to a stop. And this is a situation when you have a perfectly working ABS system.

In other cases when the ABS light is on all the time, it means that there is something really wrong with this system.

The car basically wants to tell you that there is a problem with the ABS system. And you shouldn’t ignore this light. Why I’m saying this?

Well, because a lot of people are just ignoring this light and pretend like it’s not there. This will make things even worse because you might be having a problem with a faulty ABS system.

This means that some of the components in your ABS system have probably malfunctioned. In this situation, you will face big issues to come to a stop whenever you need this system to work. Because if the ABS light is on, your car might not be able to use the ABS system and the tires will skid and lock up.

Not an ideal situation if you have a car in front of you or a pedestrian that you might end up hitting. This is why you need to learn how to diagnose these problems and learn the basics of car diagnostics. And that’s what we are going to cover next before we learn why is my ABS light on. So, follow along.

Introduction To Car Diagnostics

Now before we cover the causes of why is my ABS light on, let’s introduce ourselves to car diagnostics and learn the basic stuff that you will need when it comes to fixing a problem like this in your car.

Modern cars are so packed with technology, that is almost impossible to diagnose problems without computer diagnostics.

There are a ton of sensors on each car that work together and are connected with the computer, also known as the PCM.

But when it comes to the ABS system it is worth noting that this system is separate from the PCM and is basically running with the ABS control module.

This module controls the hydraulic pump of the ABS system and determines when to activate this system.

But still, you can get access to it with a simple OBD2 scanner. Just get a good quality scanner and give it a good scan. It should show the error codes that the system is producing as well as the causes of why this problem is happening to you.

Then after you completed the scanning process, you can move on to troubleshooting the matter. And for this, you will need a little bit of ingenuity as well as a multimeter tool.

With this multimeter, you will be able to measure some values that are essential when it comes to determining if a component is faulty or not.

This tool can save you hundreds of dollars that you could spend on replacing components that are actually good. That’s why you need how to use one of these tools as well. With them, you can measure, resistance, continuity, as well as voltage. So, grab one before you dive into diagnostics. But why is my abs light on? Let’s see that next.

Why Is My ABS Light On?

Now as we covered the basics of the ABS system and learned the ABS meaning, let’s now focus on why is my ABS light on? What are the main causes for this light?

This is crucial information for you to know because it will help you a lot when it comes to diagnosing and troubleshooting the problem. Knowing the causes will tell you basically where to look for your problem and fix it the fastest you can. That’s why in the following chapters, we are going to elaborate on the main causes in-depth so you get the right perspective. So, let’s begin discussing.

1. A Blown Fuse

The simplest thing that could make you wonder why is my ABS light on is a simple blown fuse. These fuses tend to pop and when they do, basically your whole ABS system is down. But why is this the case?

Well, this is the car safety system. Whenever there is a short in the electrical system, a fuse might blow in order to prevent further damage to other components or also to avoid the possible risk of fire.

Yes, that’s right. If there were no fuses around, you might be having troubles bigger than the ABS system and cars would have been a lot more dangerous to drive.

Luckily someone has invented these fuses. Whenever there is too much power in a specific system, a fuse will pop instead of bigger damage being created and possibly fire in the engine bay. That’s why it is often useful for you to check the fusebox and make sure that the fuses are all in good condition.

Remove the plastic cover of the fusebox and at the rear, you will notice the diagram to see which fuse does what. If there is a bad fuse concerning the ABS system, replace it. Now let’s discuss the next probable cause of why is my ABS light on.

2. Bad Speed Sensor

The second very probable reason why is my ABS light on is the problem with the speed sensor. These speed sensors can fail and cause a lot of trouble for car owners, including this type of issue with the ABS light on. So, why is this the case?

Well, this is the case because this speed sensor is basically observing the speed at which the wheel rotates and if there is an abrupt stopping it will send information to the ABS module and tell it that the car needs to stop. So, then the ABS system turns on. If you want to learn more, check out our guide on the ABS system repair cost and how much is the ABS module replacement cost.

There is a total of four sensors. One sensor per wheel. These sensors are usually mounted behind the wheel. And if you turn the steering completely left or right you will be able to see them. They are really simple to replace and are one of the most frequent causes of the problem of why is my ABS light on. Now let’s move on to the next probable cause.

3. Bad Speed Sensor Tone Ring

The third most common cause for the problem of why is my ABS light on is a bad speed sensor tone ring. But what is this ring all about?

Well, the speed sensor has to take the measurement from somewhere. And that place is the tone ring. This is a ring that is mounted on the wheel. So, as the wheel turns, the speed sensor gets the reading from it.

But sometimes this ring can get clogged with debris and dirt, or possibly rust and this can greatly impair the ABS system from working properly.

So, if you start to experience some problems and the ABS sensor is good, then the tone ring might be the cause of your trouble and it is worth checking it out. Now let’s move to the next probable cause for why is my ABS light on.

4. Bad ABS Module

Another very common cause of why is my ABS light on is a bad ABS module. This module is basically the brain of the ABS system. So, you can imagine what will happen when this module doesn’t function as it should.

Remember that this is an electronic device and electronics can go away after a lot of years of use. Even though, there are cars that are more prone to these problems since their modules were supplied by manufacturers that produced them from low-grade materials.

Whenever this type of module breaks, it will be expensive to fix. That’s why you don’t want to have to replace this component on your car. But sometimes to sort the problem of why is my ABS light on, you just have to do so to get things done.

5. Bad ABS Hydraulic Pump

Another very probable reason for why is my ABS light on is a bad hydraulic pump. This hydraulic pump is a really essential component of the ABS system.

Namely, this pump helps to pump the hydraulic fluid into the ABS system and make your car stop. Without this pump delivering the right hydraulic force and the pressure needed, the ABS system will not function as it should.

This is also another really expensive component to replace in order to fix your ABS system. So, you don’t want to have this problem.

This is why you need to do research before purchasing. Make sure that you find a car that is less prone to these ABS pump failures. You just don’t want to replace any of these parts. Now let’s move to the next probable cause for why is my ABS light on.

6. Low Brake Fluid In The System

Another probable cause of why is my ABS light on is the situation when you have low brake fluid. If you are running low on fluid, you are highly likely that you will face problems like this. Why is this the case?

Well, this is the case because the ABS pump needs hydraulic pressure in the system to work. So, whenever there is not enough pressure in the system. You will highly likely be struggling with your brakes as well as with problems with the ABS. So, make sure that you top off the fluid whenever you notice something like the situation of why is my ABS light on.

7. Air In The Brake System

And the last cause for why is my ABS light on is air in the brake system. If your car often is running low on fluid and has leaks in the brake system, you will experience problems with the ABS system like this with the ABS + the brake light on.

So, in this case, your top priority would be to fix the leak first and clear the system from the air that has entered. That’s how you can be sure that you don’t have problems like this in the near future.

This is why you need to look at simple things like this at first before you jump to conclusions that you have problems with the ABS pump or some other very expensive component.

But how can we diagnose the problem why is my ABS light on? Well, that’s what we are going to cover next.

How To Diagnose & Fix An ABS Light?

We learned why is my ABS light on, now let’s focus on diagnosing and fixing this issue on your car. What should be your plan of attack and how to tackle this issue? Let’s elaborate.

The first thing that you want to do whenever you have a problem like this is to check the fusebox and see if the fuses for the ABS system are good. If they are blown, you will have to replace them to fix this issue. Simple as that.

The second thing you want to check is the level of fluid in the system. If the fluid is low and you have a leak, you should focus on sorting this problem out. Only that way you will fix the problem with your ABS.

The next thing that you want to check is the codes that the ABS system produces. Get an OBD2 scanner and scan the car for codes. This is the way you find problems with the system itself and move on from there.

There could be a number of codes that indicate issues with the speed sensor, control module, and hydraulic pump. Depending on the codes you get, you should look to solve the problem.

If a speed sensor produces a code, you might be needing to check the specific sensor with a multimeter and determine if it’s working or not.

Similar to the ABS control module and the hydraulic pump. All these components have to be checked if you get any codes that are related to them.

The last thing will require replacing the faulty component with a new one. Some of these components can be really expensive. But sometimes that’s the price to pay when it comes to the problem of why is my ABS light on.

Cost To Fix The ABS Light

So, what is the cost to fix the problem of why is my ABS light on? Well, that can really depend much on the issue that is causing the problem itself.

Why Is My ABS Light On

If it’s a simple speed sensor, you can replace it for $30. But if it’s something more expensive such as a control module or possibly a faulty hydraulic pump, you can expect to pay more than $500 to sort these things out. Also, the labor is somewhere between $50 and $100 per hour.

Conclusion To Why Is My ABS Light On

In this article, we have covered quite a bit when it comes to the question of why is my ABS light on. First, we learned what is the ABS system in general and how it works.

Then we have covered the basics of car diagnostics and the probable causes for the problem with the ABS light. After, we learned how you can diagnose and fix the problem and at what cost will this be possible.


Now let’s answer some frequently asked questions.

What Is ABS

ABS is a safety system that prevents the wheels from locking up under hard braking situations. It helps the car to stop at a shorter distance compared without this system.

What Does ABS Stand For

ABS stands for Anti Lock Brake System. This system basically prevents your car’s brakes from locking up under hard braking and improves the stopping distance significantly.

What Does ABS Mean On A Car

This abbreviation is referring to the anti-lock brake system that is installed on almost every modern car out there. This system is really effective and helps your car to stop at a shorter distance than when it is not equipped with this system. And also prevents creating flat spots on your tires as well.

Why Is My ABS And Traction Control Light On

This is the case because you probably have some defect in the speed sensor of one of your wheels. Both the traction control and the ABS rely on this sensor and whenever this sensor is not working you might experience something like this.

Why Is My ABS And Brake Light On

This is often caused by low brake fluid or any other malfunction in the brake system like air in the system, etc. You need to check your system for leaks and top off the fluid first and then move on to other probable causes such as the speed sensor and other components.

Why Is My ABS Light On After Replacing Brake Pads

This is probably a malfunction in the ABS system or you have installed the brake pads in the wrong way. You can try unplugging the positive terminal of the battery to reset the computer and see if this helps.

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