How EBD Works

EBD stands for Electronic Brake-force Distribution. But what exactly does this system do, and how EBD works for drivers?

You might have heard of a brake corrector. If not, have you perhaps heard of the fifth brake cylinder? No? Let’s break it down in simple terms to make it clearer.

What is the Fifth Brake Cylinder and How It Relates to EBD

The proper term is a brake corrector. It regulates the braking force on the rear wheels, depending on the load on the rear axle. The heavier the car, the more braking force you need.

The brake corrector physically connects to the suspension. As the car lowers under load, it adjusts the braking force.

During sharp braking, the front of the vehicle dips, while the rear lifts. This happens because the mass shifts from the rear to the front axle.

As a result, the load on the rear wheels decreases, meaning you need less braking force to prevent the wheels from locking and losing control.

In these situations, the brake corrector reduces the braking force on the rear wheels. Once braking stops and the rear lowers again, it restores the braking force to its original level.

Although this is a simplified explanation, there’s more to discuss. For example, many older cars have had their brake correctors removed. Even after removal, many owners continue driving without issues, often unaware that it was removed or that the car even had one if they bought a used vehicle.

For a visual explanation, check out this video on EBD.

A “New” Solution to Understand How EBD Works

Today, almost every car less than 10 years old comes equipped with ABS. Since ABS controls the braking force on each wheel individually (if it’s four-channel), engineers developed a new solution. Instead of relying on the traditional brake corrector, they used this system to regulate braking force.

Thus, electronic brake-force distribution, or EBD, was created. To understand how EBD works, it’s important to note that EBD cannot function without ABS.

EBD tracks data from various sensors, such as wheel speed and brake fluid pressure. It also uses yaw sensors from the ESP and sensors that monitor steering wheel movement.

With this data, the computer calculates which wheels are under more or less load and adjusts the braking force accordingly.

There are different types of this system. Some offer better software, more sensors, and faster processing speeds. Others are simpler and rely solely on ABS hardware.

If you know a more detailed yet easy-to-understand explanation of how EBD works, feel free to share it in the comments.

How EBD Works Compared to ABS: Key Differences

To grasp how EBD works, it helps to understand the relationship between EBD and ABS. EBD acts as a software add-on to ABS. It replaces the brake corrector (the fifth brake cylinder) and adjusts the braking force on each wheel based on the current driving situation.

In short, EBD is a subsystem of ABS.

What to Do if EBD Fails: Important Considerations

If EBD fails, ABS (and ESP/ESC, if present) likely fails as well. The brakes will work as if the car lacks both systems. Therefore, we recommend visiting a service center right away.

For more information on brake systems and their importance, check out our article on How ABS Works and Its Importance.