Amflow: Bike power motor restricted, Speed sensor error

[FlorianLanua]

Hello everyone,

I wanted to share a frustrating issue I'm experiencing with my new DJI Amflow PL Carbon e-bike in the hope of raising awareness within the community and documenting the support process for others.

I don't want to blame anyone, I just want to share the problem I'm having with a bike that's less than a month old, and how it's being solved by the manufacturer, its warranty service, and the dealer where I bought it. Everyone can draw their own conclusions.

I bought my bike just a month ago (23.07.2025) from an official dealer. For the first 400 kilometers, the bike was an absolute joy to ride—pure perfection.

Less than a month from purchase day, on 19.08.2025 everything changed. While on a ride, I suddenly felt a significant and sharp drop in motor power. The display showed the error "Bike power motor restricted," and the DJI app notified me with a "speed sensor error." At the same time, the speed reading on the display started showing random, fluctuating numbers.

I've tried restarting the bike, which temporarily resolves the issue, but the error always returns shortly after.

What's incredibly frustrating is that this is a brand new, premium bike, and I'm already dealing with a core technical fault. I've performed the basic checks myself, confirming that the speed sensor and the magnet on the wheel appear to be correctly aligned and that the cable looks fine.

I'm scheduled to bring the bike to the service center to have it professionally diagnosed. I am creating this thread to let you all know that this problem exists. I will provide regular updates here on how DJI's customer support and the service center handle this under warranty.

 

[FlorianLanua]

Continuation of the story:

That same evening, on 19 August, I contacted Amflow's support service, where I described the problem in great detail, including photos. They responded fairly quickly:

Thank you for contacting Amflow Customer Support. We are grateful to assist you with your concern.
We understand your situation. Normally, there will be three main causes of the speed sensor error:

1. The connection problem. Sometimes, reconnecting the cable from the motor will be helpful.
2. The rear wheel got loose or the thru-axle is loose. The solution will be to remount the rear wheel.
3. The sensor is damaged or the surface of the sensor got covered with mud. If cleaning the surface of the sensor does not help, it is possible that the sensor is faulty.

Based on your description, this is very likely the second possibility. We recommend you remove the rear wheel to inspect the surface of the speed sensor and the grid plate, then reassemble the rear wheel. For the thru-axle, the standard torque value is 10N·m. Please let us know any further updates.

Additionally, we would like to know if you ordered the bicycle from local resellers or the official site of Amflow.


After that, I went to the local service center where I gave them this email with a request to do everything as written here. The mechanics did everything as instructed and returned my bike to me. I rode off and after 4 kilometres, the motor power dropped sharply, and the same errors appeared.

 

[FlorianLanua]

Continuation of the story:

On August 21, I wrote back to Amflow Support to say that the mechanic at the service center did everything you asked and unfortunately the problem is not resolved. I received a reply from Amflow Support on August 22:

Thank you very much for your cooperation.
Based on your feedback, we believe it is most likely an issue with the wheel speed sensor. We would be happy to send you a replacement; however, we are sorry to inform you that our European warehouse is currently out of stock and the next shipment is expected in mid-September. If you need a faster solution, we recommend contacting your local store to have the wheel speed sensor replaced.



I contacted the authorized dealer where I bought my bike and they told me that they don't have this Wheel speed sensor in stock and they don't know when it will be available!!!!

I found this part at one of the authorized dealers and bought it with my own money as it is not that expensive and I didn't want to waste time. I received the part on August 25th and on August 27th the mechanics of the store where I bought the bike installed it for me. Immediately after installation I did a little test drive and everything was ok.

But the next day on August 28, the problem came back and the same thing happened:
The display showed the error "Bike power motor restricted," and the DJI app notified me with a "speed sensor error." At the same time, the speed reading on the display started showing random, fluctuating numbers.



To be continued...

 

[Worten]

It turns out that their warranty service is complete rubbish if they point out a problem with a specific part and at the same time tell you that you have to go without your bike for a month because they don't have that part. And this is what the manufacturer says.
I wonder how your story will end. I've read about the same problem with other users, and it was only solved by replacing the motor.

 

[Paul F]

I would get the motor replaced with a new sensor ASAP.

 

[jackamo]

Ah the old switch it off switch it on didn't work followed by the standard lame oh try this ...
Funny how most ebike manufacturers use the same customer service notes..

I do hope you get it sorted though as it's a lot of cash sitting doing nothing

 

[Rolf]

Thank you for the detailed description. I received the same error message today and had to cut short my tour in the mountains. Based on your description, I will first clean the speed sensor. I will keep you updated.

 

[FlorianLanua]

Hello, everyone!
Now we can sum up this whole story.
As I wrote earlier, replacing the speed sensor did not help.
In the end, Amflow sent to my home address a new motor, which was replaced at an official dealer, and the problem was solved. I sent the old motor back to them.

I would like to note that the support service ([email protected]) responded to my emails within 24 hours, and I would like to express my sincere gratitude to them for that.

Good luck and happy rides to everyone!

 

[Rolf]

Thanks for sharing. After washing my bike and cleaning the speed sensor later this week, I took a short ride of an hour about, today before we expected the rain to start, and it went well so far. Let's hope again

 

[thaeber]

Same here. Went thru 3 speed sonsors. Problem not solved. Now my bike is back at the shop waiting for motor replacement. Really frustrating.
My bike first failed after a heavy rain ride, suspect the controller took damage due to a shortcut at speed sensor. I would recommend to seal the speed sensor connection, and to avoid pressure washing.

 

[JonoHobart]

I have a friend who believe it or not we’re not able to solve the error message by all the usual shenanigans had his motor replaced. That was only about eight weeks ago, yet today after replacing brake pads cleaning disc rotor And reassembling. He went for a short ride only to find the error message suddenly pop-up. I mean all is done is do simple technical work at the back end nothing to do with the motor. Does anyone have any sense of what might have happened? He tells me there is no grease or oil or mud covering any surfaces.

 

[Hicksy 92]

How are you supposed to keep the speed sensor clean on a mountain bike especially in the uk

 

[Rolf]

Thanks for sharing. After washing my bike and cleaning the speed sensor later this week, I took a short ride of an hour about, today before we expected the rain to start, and it went well so far. Let's hope again

 

[Rolf]

Just a short update from my side: Since my cleaning of the speed sensor and short test ride thereafter, about a month ago, I made three major tours since into the Swiss Alps, about 6 hours, 11o km, 2600 meters of elevation gain and no serious problem again. However, I remember a situation, when I was going uphill, I realized that the engine was starting to slow down actively exactly at the moment when I switched and reduced the support form the motor from trial mode to automatic. I suddenly eased off the pressure on the pedals, switched back to trail mode for a short time, and just 1-2 minutes later everything was fine again. But the uncertainty on the trial ride remains. That's unfortunately a bit a shame for such a great bike.

 

[thaeber]

My Motor replacement was approved by Amflow, bike will be back from the bikeshop by end of this week. Hope the problem is solved then, I‘ll give an update later the year.

 

[nrgbod]

My Motor replacement was approved by Amflow, bike will be back from the bikeshop by end of this week. Hope the problem is solved then, I‘ll give an update later the year.

I had the same problem with speed sensor error.
I took it to the bike shop 7 days ago and received it back today with a new motor fitted.
Superb service from Amflow/ DJI.
The only problem I have now is my bike seems to be stuck in EU. I can't seem to get it to go back to Latvia

 

[JonoHobart]

Has anybody actually been told why they need a new motor and what specifically has been the problem? I have had no luck even with flow engineering support in them being able to tell me anything that seems to be ever wrong with the Motors that they have had returned. They continue to sprout damage to the sensor or a failure of the sensor or a failure of the rear wheel distance to the sensor along with potential water ingress to the motor. If it is water ingress to the motor, how the heck can we prevent this?

 

[thaeber]

My motor started to throw speed sensor error after a heavy rain ride. I suspect water ingress on speed sensor connection caused a shortcut and damaged the controller. But that’s only guessing. I will use a shrink tube to seal the connection when the bike is back.

 

[nrgbod]

Has anybody actually been told why they need a new motor and what specifically has been the problem? I have had no luck even with flow engineering support in them being able to tell me anything that seems to be ever wrong with the Motors that they have had returned. They continue to sprout damage to the sensor or a failure of the sensor or a failure of the rear wheel distance to the sensor along with potential water ingress to the motor. If it is water ingress to the motor, how the heck can we prevent this?

The shop tested mine by substitution, my original speed sensor tested ok on a different bike and my original motor gave the same error with a new speed sensor.
I suspect the sensor cables may be breaking on the motor side of the junction but thats just a guess.
My motor hasn't been near water for at least six months so don't think my failure had anything to do with water ingress.

 

[thaeber]

The shop tested mine by substitution, my original speed sensor tested ok on a different bike and my original motor gave the same error with a new speed sensor.
I suspect the sensor cables may be breaking on the motor side of the junction but thats just a guess.
My motor hasn't been near water for at least six months so don't think my failure had anything to do with water ingress.

Same with my speed sensor, worked fine on other bikes. Interesting that Your failure occurred without any water involved.

 

[JonoHobart]

I smell a rat and I can’t understand why these motors are being replaced rather than just a sensor or sensor cable. Clearly there is something more sinister within the engine electronics at play that can’t be swapped out. I wonder if they are working on a completely new Setup and just too scared to tell us what’s really going on?

 

[thaeber]

I smell a rat and I can’t understand why these motors are being replaced rather than just a sensor or sensor cable. Clearly there is something more sinister within the engine electronics at play that can’t be swapped out. I wonder if they are working on a completely new Setup and just too scared to tell us what’s really going on?

Because it’s not a sensor or sensor cable problem? If it’s a controller topic, you cannot ask the bike shop to open the motor and replace the controller. So You exchange the motor. If the failure rate is very low (and that’s the assumption here) thats a common practice across many industries to keep customer satisfaction up. In the background you work on the problem and solve it.

 

[JonoHobart]

I just wished they’d tell us this directly. I have contacted the engineers via support, and it seems to be the party line not to mention anything about anything happening at the motor end. I have a colleague with the same bike as mine who has had now two replacement motors for the same issue.Each time it’s been insinuated that it has been his fault even though they have accepted the warranty claim. My issue so far has luckily been fixed by tightening the axle of course. I guess I’m just waiting for the ultimate process of that not being the real cause. Oh well, great Bike nonetheless.

 

[thaeber]

I just wished they’d tell us this directly. I have contacted the engineers via support, and it seems to be the party line not to mention anything about anything happening at the motor end. I have a colleague with the same bike as mine who has had now two replacement motors for the same issue.Each time it’s been insinuated that it has been his fault even though they have accepted the warranty claim. My issue so far has luckily been fixed by tightening the axle of course. I guess I’m just waiting for the ultimate process of that not being the real cause. Oh well, great Bike nonetheless.

Got Your point- would be nice to have full transparency. But that’s not common practice within the Ebike industry, unfortunately. Instead they try to hide the problems (remember the Brose belt or Bosch water ingress issues), keep customers calm by replacing motors / convenient warranty policies, cross fingers that it will not be a major failure and improve their products silently. Future will tell if this is the right strategy…

 

[Tony4wd]

Probably won't know the exact cause of the problem until after-market repairers are fixing the motor out of warranty. The internal electronics are tiny in comparison to Bosch, so possibly something in the first gen motor isn't quite robust enough:

 

[thaeber]

New motor, same shit…got my motor replaced, first ride, speedsensor error - motor power restricted! Bike is back at the dealer - no clue what to do now. Very disappointing…

 

[Veefour]

I had an issue with my rear axle and damaged the speed sensor. The shop where I bought it replaced the sensor, first ride out I had this same issue. Not great to hear others having the same problem and a motor swap is required. Hopefully Amflow can resolve it for me.

 

[rigavaz]

My bike produced the same problem. Waiting for replacement sensor Amflow will send out.
I truly hope this is not the start of a similar lengthy story….

Anybody who’s issue was actually solved by sensor replacement?

 

[The Muncher Monster]

I'm at the start of this journey, after a wet ride at Peaslake the sensor packed up, it came back to life briefly but then died again. Tightened / re-seated everything, even tried loosening the sensor so it was closer to the rotor. Waiting for Amflow support to decide the next step.

 

[thaeber]

New motor, same shit…got my motor replaced, first ride, speedsensor error - motor power restricted! Bike is back at the dealer - no clue what to do now. Very disappointing…

My Problem was solved by mounting 1 mm spacers between signal disc and brake disc to narrow the distance to speed sensor. Obviously this tolerance is quite crucial, running a different wheel with slightly different disc position can cause this issue. Should be mentioned in the manual imho.