How Do You Test An Ebike Brake Sensor? (Solved)

The brake sensor in an electric bike is a very important part of the brake operation, which can affect your safety while riding an electric bike

In this post, we will explain how to test the brake sensor, how it works, what code will appear to you in the event of an error in the sensor, as well as ways to fix it.

What is the brake sensor & what it is used for?

The electric bike sensor is consists of two parts, the first part is the read switch or the sensor plate, and the second part is a magnet, and the function of this sensor is to cut off the electric current from the motor in the event of pulling the brake lever in order for the bike to stop faster.

Why the Brake sensor is important for you?

Sometimes I hear words from my friends that the brake sensor is not important or that they are canceling it, and I really don’t see any logic in this.

This is for two main reasons

1- Safety while riding.

The brake sensor is very important to protect you and the people around you while you are driving. You can imagine that without the brake sensor, there would be a difference of three to four seconds for the electric bike to stop.

And maybe in some situations, you may need only one second to save your life or the lives of people around you.

2- It’s requested by low

The brake sensor is a necessity and required by many states in the United States of America by force of law

Even if you live outside the United States, most countries now tend to put in place laws to regulate and protect cyclists as well as ordinary people, and one of the most important safety factors required is the presence of a brake sensor that can stop the bike in the shortest possible time

How Do You Test An Ebike Brake Sensor?

Before we explain how to test the brake sensor, perhaps we should first point out when you should think about testing the sensor.

Are there signs that there may be a problem with the brake sensor?

In fact, there are two very famous signs by which you can decide that you should test a brake sensor:

1-The electric bike stopped working.

In the event that the battery of your electric bike is charged and the controller is working properly, and there are also no sounds coming from the motor, this means that the reason for the inability of the bike to move is the brake sensor.

Check out our recommended ebike brake sensor on Amazon from here

2-Error Code 25

If you start the electric bike and an error 25 appears in front of you on the screen, this means that there is something wrong with the brake sensor.

In the next part, we will explain how to solve Error 25.

Now that you know what the signs indicate that there is a problem with the brake sensor, let’s start with how to test


To do a brake sensor test, you can do this in two ways.

Testing Built-in Brake sensor

First method: It is to ensure that all parts of the sensor are connected correctly, and I mean here by correctly that the cable for the sensor is connected to the controller, and also that there is no loosening in the screws or in the magnets.

The second method: is to remove the cable for each lever separately and operate the electric bike.

Note, you must determine which of the brake lever has a problem, so you must disconnect each cable separately.

The previous method can be used if the sensor is built-in to the brakes of the electric bike, but if the sensor is externally installed, you can test it using the multimeter

Check out our recommended ebike brake sensor on Amazon from here

How to test the external brake sensor using a multimeter?

In order to make sure that the sensor is working properly, you should follow the below steps.

1-put the two ends of the multimeter inside the plug (you  should find reading on the multimeter)

2- put the magnet on the sensor plate. ( in this case, you should not see any numbers on the millimeter)

And in the event that you found readings, this means that the sensor is not working properly because it does not cut the current.

Check out our recommended Multimeter on Amazon from here

How to solve Error 25 on your ebike?

As we mentioned earlier, error 25 means that there is a problem with the brake sensor.

This problem is mostly due to two reasons.

The first reason for error 25: is that the magnets are not attached to the sensor plate, and this is due to the fact that the magnet is not installed well or that the sensor plate is not well installed, and all you have to do in this case is to make sure that all the parts are installed correctly.

The second reason for error 25: is that the cable coming out of the brake lever is not connected well with the controller, and here it must be ensured that the connection is good.


As a general rule, you can test the brake sensor using the multimeter by connecting the poles of the multimeter in the sensor’s connector with the magnet attached to the sensor. If the sensor is working, you will not see any reading on the multimeter, but if there is a reading, this indicates that the sensor is not working properly.

On the other hand, if you do not have a multimeter or your brake sensor is built-in you can test the brake sensor by removing each cable from the brake lever cables connected to the controller separately and experimenting with running the bike to determine which of them is causing the malfunction.

Useful Resources.

How To Test An EBike Controller At Home? (Explained)  : this post has some basic tips with pictures for how to use the multimeter.

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