How do I fix the pedal assist on my ebike? (6 Fixes)


Although the PAS Sensor is very important in an electric bike, knowing the problems that may occur to it is very easy and does not require previous experience.

On the other hand, solving these problems also does not require experience, but it needs a little scrutiny in order to be able to solve the problem.

In this post, I will share with you the method of testing the PAS cadence  Sensor on the electric bike, as well as the most common problems that occur to it, as well as the method of fixing them.

Note: you can check the below post for PAS with Torque sensor issues & replacement

How To Replace Ebike Torque Sensor? (Guide With PICs)

How To Test ebike PAS sensor?

In order to do a test your ebike PAS sensor, you must first eliminate all the factors that hinder its work in the normal cases, which are the front brakes and the rear brakes, because the nature of the brake work is to disconnect the electricity from the motor so that the electric bike can stop.

Therefore, before testing, all brake cables connected to the motor must be disconnected.

Then you should lift the bike off the ground during the test.

Finally, set the PAS settings to speed to 3 or higher.

turning the crank clockwise.

To summarize: The PAS sensor is tested by disconnecting the front and rear brake cables, then lifting the bike off the ground and rotating the crank clockwise. If the motor moves normally, the problem may be in the front or rear brakes, but if it does not move, the sensor has a problem

In the next part of the article, we will discuss together the most important issues that may occur in the electric bike PAS and how to fix them.

How do I fix the pedal assist on my ebike?

As a general rule, you can solve the PAS problems by making sure the distance between the magnet and the sensor is precisely set, and also that there is no problem in other parts of the bike that affects the work of the PAS, such as the front and rear brakes or the throttle

Now let’s get into the details of how to fix the issue that you may face with your PAS cadence sensor?

1- The bike won’t move at all. (front or Rear Brake issue)

The first problem that you may face is that the electric bike does not move completely while pressing on the crank, and this problem has several reasons that we will explain in detail.

The first reason for stopping the electric bike is that there is a problem with the front or rear brakes so that they are working all the time and therefore the motor will be closed, so no matter how much you try to press the crank, the bike will not move.

A test can be done to fix this problem by disconnecting the front brake cable and then pressing the crank clockwise.

Then the same test is repeated with the rear brake.

If the motor moves while any of the brakes (front and rear) stops, the problem is in the disconnected brakes.

Another sign from which you can determine if the brakes are what stops the PAS from working is the brake lamp that lights up during stopping.

If you find this lamp working continuously, this indicates that a defect in the brakes prevents the movement of the motor

Check Out our Recommended multimeter on Amazon 

2- The bike is not moving ( Magnit issue)

The second and most famous reason for the PAS cadence sensors is that the magnet opposite the sensor is far from the sensor, which causes the sensor to be unable to measure the movement of the magnet and causes the signal to not be sent from the sensor to the controller in order for the motor to move.

In order to solve this problem, the distance between the magnet and the sensor must be not more than 3 mm.

Check out this PAS) Easy Install – Waterproof Electric Bicycle Pedal Assist System on Amazon

3-The bike is not moving ( Magnit issue 2)

The second problem that may occur in the magnets and cause the bike not to move due to the presence of mud or dirt on the magnet itself, which will cause the sensor to be unable to sense the movement of the magnet.

To solve this problem, you should clean the magnet well and then adjust the distance between the magnet and the sensor cadence

4-Bike cut out during increasing PAS Speed.

when the electric bike Cuts off while increasing the speed of the PAS is considered evidence that the magnet or the sensor is not installed in its place correctly because what causes this cutting is that the sensor or magnet moves while riding the bike, which causes the sensor to be unable to send the signal to the controller correctly.

To solve this problem, you must make sure that the sensor and magnet are installed well, and you can do this by using cable ties.

you can also see this video for DIY fixing the PAS.


5- eBike won’t move  ( Sensor cable issue)

One of the problems that may cause the PAS to be unable to function properly is that there is a problem with the cable connecting the sensor and the controller.

To solve this problem, you should check that the cable is connected correctly and that the cable is not broken

You can also measure the voltage using the electric bike tester.

6- ebike won’t move (throttle issue)

If you have an electric bike with a throttle and a PAS, it is possible that a problem with the throttle may affect the operation of the PAS
But it should be noted here that this does not happen often.

In order to know the problem in the PAS or the throttle, you will disconnect the throttle cable and try the PAS. If the bike moves, the throttle is what causes this problem (you must also disconnect the brake cables)

Useful Resources:

Ebike Cadence VS Torque Sensor The Difference & How To Use

How Do You Test An e-bike Throttle? (Step by Step) 

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

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