Why does the ABS light go on and off?

A vehicle’s ABS light will usually go on when there is a problem with the braking system. For example, it might mean that your brakes are malfunctioning, and your car might not stop the car efficiently if you hit the brake pedal.

If the ABS light stays on, it could mean that the problem is major, like a faulty wiring harness or wheel speed sensor. But what does it mean when the ABS light goes on and off?

An ABS light that turns on then goes off, or is flashing, might indicate a minor problem with your vehicle’s braking system. You could just be driving along when you notice the light go on only to go off after a moment and repeat the cycle.

A flashing ABS light can also mean that the module is malfunctioning, and it will give the Electronic Control Unit wrong information that can also be bad for other braking components.

There could be several reasons behind this, as clearly explained in this article.

What does ABS flashing mean?

The vehicle ABS is designed to contain sensors at each wheel that monitor the rotational speed during movement. The car’s electronic control unit monitors, and looks out for abnormal signals from the four wheels or brake pedal that could interfere with the car’s stability.

If there is no signal from the vehicle’s ABS sensors, the computer monitor turns on the ABS warning light to warn the driver of a potential problem.

In addition to monitoring signals from the wheel speed sensors, the computer monitor can turn on the ABS light for other reasons, such as a blown fuse or low brake fluid levels. Flashing refers to when the ABS light goes on and off intermittently rather than staying on during a drive.

A blinking ABS light usually indicates a minor problem with the system that could be as simple as dirt build-up or a sign of damaged modules. 

Some ABS systems are designed to flash on the severity of the problem in the car. For example, it will blink more times for major problems and once or twice for a minor issue. For a clear interpretation of what your vehicle’s ABS warning light indicates, you should consult your vehicle repair guide or visit your local mechanic.

It can happen that after a repair, the mechanics forgot to connect the previously removed wires, so the ABS indicator on the panel remains on. This issue usually triggers the ABS light to illuminate when starting, and after a while goes out while driving. Thus, you should inspect the wire connections

What causes the ABS light to Go on?

The most common behavior observed with ABS lights is going on while you are driving and staying that way. Several problems could be behind this signal, some of which include:

1. Malfunctioning ABS Module

Your vehicle’s ABS shares some vital components with other systems in your vehicle, such as the traction control system, which is designed to ensure all the wheels are on the ground and rolling smoothly. Since these systems share a self-diagnostic system and control module, sometimes an issue with the traction control could turn on your ABS light.

Both a software failure and damage to the control unit itself can occur. In this case, you need in-depth specialized diagnostics, repair, or replacement of the electronic module.

2. Low Brake Fluid Levels

Your vehicle’s braking system is hydraulic. If the fluid inside it is exposed to evaporation or there is a slow leak, the brakes could malfunction. The computer monitors in your vehicle usually detect this and, in turn, turn on the ABS light.

3. Damaged Speed Sensors

Wheel speed sensors are in charge of detecting if your wheels are moving abnormally, and then your traction control system makes the required adjustments on each wheel. If the speed sensors stop working, they could relay inaccurate information and hence, disable your ABS.

What should you do about the ABS light?

You might be driving when you notice that the ABS light is illuminated on your car’s dashboard. We have already established that this light indicates an issue with the anti-lock braking system. Therefore, it is advisable to quickly stop your car and check on the light to avoid a car accident or system malfunction.

If there are problems with the ABS unit, then it will be problematic to eliminate them. It can be detected using a scanner, which will show the system error code. Based on the information received, the problem with anti-blocking is known.

If it is not possible to check the errors, you can try to do the following:

  • accelerate the car on a flat road up to 40 km/h or 25 mph;
  • make sure that sudden braking will not create problems for other drivers;
  • sharply press on the brake pedal to stop the completely;

In some cases, performing the above steps, the ABS light goes out, and the anti-lock braking system is active again. If this does not help, then the matter is not in electronic failures, there might be more serious issues.

It will not be possible to replace the ABS sensor on your own. You should then consult with your mechanic on the best way to handle the matter.

You might need to take your car in for an inspection using a scanner. You could examine the fuse box to see if a related fuse is broken.

ABS can be covered with dirt on its working surface, which is located on the wheel. In this situation, it is enough to wash the car for the ABS indicator to go out.


Recent car models contain numerous sensors and warning lights responsible for alerting you to any issues with your vehicle.

These warning lights warn you of various potential problems, from reminding you to fasten your seat belt to alerting you that your car is low on oil. While all these sensors are crucial, the ABS braking system is arguably one of the most important.

This is why intermittent ABS light blinking can be such a headache. If you experience it, you should take your car to a certified mechanic for a professional inspection.

In any case, if the ABS is on, it should be borne in mind that the anti-lock braking system is disabled, and hard braking will cause the wheels to lock. 

For this reason, it is important to avoid situations where emergency braking is required and to detect and eliminate the malfunction as soon as possible

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