If you see both the ABS light and brake light on,then without a doubt, you can conclude that your vehicle is facing some sort of issue with the braking system.
The possible causes can include:
- Faulty components in the braking system
- A problemin the system UI
- ABS malfunction
Understanding Brake Light& ABS Light
First, you will need to understand what they are and how they work to find out why your ABS light and brake light are illuminating.
The bake light is part of the braking system of a vehicle. This system consists of the following:
- Brake Fluid & Fluid Reservoir
- Brake Master Cylinder
- Brake Pads
- Brake Lines
- Brake Pedal Switch
- Brake Calipers
In a car, the braking system starts to work when the driver presses the pedal, which pressurizes the brake fluid by the master cylinder.
The fluid then goes to the brake calipers, and it applies the brake pads directly to the rotors, making the wheels slow down or come to a stop.
So, when the brake system doesn’t start to work like this, your vehicle’s system UI will try to notify you by turning on the brake light.
ABS light is part of a vehicle’s Anti-lock Braking System. And from the name, you can guess that the braking system is directly connected to the ABS; therefore, whenever the braking light comes on, the ABS light also turns on.
The Anti-lock Braking system utilizes the following components:
- Wheel Sensors
- ECU or System Control Module
- HCU or Hydraulic Control Unit
- ABS Motor/Pump
- ABS Modulator
- Breaking System
This system comes alive as soon as the vehicle starts; it will first make a system check to ensure everything is in order. The ABS light will be illuminated during this process. After that, if no problem is found, the ABS light will turn off.
The wheel speed sensors will monitor the rotational speed continuously. If there is any anomaly, they will instantly report it to the system control unit or ECU,which will activate the ABS.
Once it is active, the system control module will direct the HCU and the modulator to adjust the brake pressure on the wheels.
They do this by opening & closing the solenoid valves, which prevents the wheel from locking up as you brake. This allows you to maintain steering control in tough situations.
But when any of the components fail to respond to the command of ECU, the system will think of this as a malfunction and turn on the ABS light so that the driver can understand that the ABS no longer protects them.
Potential Reasons for ABS/Brake Light On and How to Fix Them
When any of the components of the mentioned two system starts to fail or malfunction, you will see the ABS light and the brake light illuminate on your vehicle’s dashboard.
To solve this problem, you can follow the given solutions:
Balance the Brake Fluid Level
One of the most common reasons we encounter brake and ABS light tuning is the brake fluid level.
If it goes down to a certain amount, the braking system will automatically shut itself up, which results in the lights coming on from your dashboard.
In this case, just filling up the brake fluid tank should fix your issue. Make sure that there is no leak happening from the fluid tank either.
Another fact that many forget is choosing the right brake fluid. Every car has a different type of brake fluid dependency. Contact the manufacturer to find out yours.
Repair or Replace the Brake Master Cylinder
Unless your car has been through serious accidents, your brake master cylinder shouldn’t be damaged. But in some rare cases, where it gets damaged, you can bring it to a professional to repair it.
That being said, the best possible solution would be to replace it completely. A faulty brake master cylinder can damage the other component of the braking system and even lead to accidents if you are not careful.
Inspect the Brake Pads
Brake pads do the heavy work for you when you are braking, so if the brake light and ABS light are on, then it is a high possibility that they are the ones who need an inspection.
You will need to use a jack to lift your car first. Then remove the wheels one by one to access the brake pads. The first thing you should do is clean the pads and the surrounding area. Sometimes, dust and dirt accumulate, which makes the pad non-functional.
But if the pads are heavily worn out, you will have to replace them with new ones.
Look into Brake Pedal
The brake pedal initiates the entire braking system, and if that fails to work, you can be sure that you will be notified by the brake light coming on.
Check if the brake pedal switch is working properly or not. You might need to get a replacement to completely get rid of this issue.
Clean & Replace the Wheel Sensors if Necessary
For the ABS system to function properly, the wheel sensors need to be active as soon as you start your engine. Most of the time, drivers see the ABS light flashing because there is something blocking the wheel sensors from working properly.
Therefore, gently clean the wheel sensors. Ensure the fact that there is nothing blocking their view. If that doesn’t fix your ABS light issue, then you will have to check each wheel sensor individually to find the faulty one and then replace it with a new sensor.
Check the ABS Fuse
The ABS fuse hosts the electrical components which power the entire ABS system. So, if it suffers from any damage or malfunction, then the whole system will stop working, and you see the ABS light blinking on your car’s dashboard.
As for the location of the fuse box, it depends from one model to another. Consult your vehicle manual or contact your manufacturer to find out where yours is placed.
Once you have found the fuse, check if it is burned or suffering from any damage. If it does, then just changing the fuse will solve your issue.
But in the worst-case scenario, the fuse can damage the surrounding components as well. If that happens, then you will need to do a complete system check to find out the exact amount of damage.
To avoid facing such a scenario, you should check the ABS fuse as soon as you see the ABS warning light illuminating on your dashboard.
Inspect the ECU & HCU
If the ECU or HCU starts to malfunction, then the ABS lights will turn on. Restarting the system can often fix the issue. But in most cases, you will have to replace them if they are the main cause.
Usually, this happens when the ABS fuse takes damage as the ECU & HCU heavily rely on the electrical power provided by the fuse.
Look for Error Codes
If you still can’t figure out the main reason why the brake light and the ABS light are turning on, then you can take your car to a mechanic who can use a diagnostic scanner to reveal error codes.
The error codes will describe which type of problem your car is actually facing, and then you can take action from that information.
Watch Out of System UI Malfunction
While it is not that common, there have been cases where not the ABS nor the braking system was faulty, but the system UI itself was malfunctioning and turning on different types of lights at random.
If that is the case with your vehicle, then you will have completely reset the vehicle system UI and the issue will be resolved.
Do keep in mind that if this problem occurs, your ABS and brake light won’t just be the ones that will be illuminating, but the entire icon collection that is found in your vehicle’s dashboard.
Is Seeing ABS & Brake Light Turn On a Serious Issue?
Yes, it is. If the ABS & brake lights are illuminating, this means that the car doesn’t have protection from the ABS or the braking system.
You will have no proper steering control, and your brakes won’t work, so slowing down becomes almost impossible.
Therefore, it becomes a safety hazard to drive a vehicle like that. If you keep going, then soon that car will face complete brake failure, and it will lead to an accident.
That is not all; driving with a malfunctioning anti-lock braking system is illegal and a complete violation of traffic laws.
So, unless you want your car not to meet the safety standards for driving on the road, you shouldn’t sleep over the ABS & brake light turning on.
Frequently asked questions (FAQs)
1. Can I drive with ABS on?
Yes, you can technically, but it is not safe to do so.
2. Is it possible to manually reset the lights?
In some systems, yes, if the lights suffer from raw physical damage. If it’s an internal software issue, then that is not the case.
3. Will disconnecting the battery reset the ABS & Brake light?
It will temporarily reset the lights, but it is not a permanent solution.
When you see both the ABS light and brake light on,you should stop your vehicle immediately and work to find a solution to turn them off. A car is not safe to drive if those lights are illuminating the dashboard.