How to Fix No Power and Exclamation Mark Errors on Electric Bikes [ADO D30C]

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I am currently reviewing the new ADO D30C electric bicycle. I really like this bike for both trail use and as a hybrid/city bike for commuting and leisure.

However, when my sample arrived, I had some issues with the motor engaging and the exclamation mark on the digital display.

Since this was a review sample shipped from the factory, I didn’t have the same level of support that you would get with a retail bike, and I had to try to communicate with the Chinese engineers. Although they tried their best to help, there were some language barriers.

With some googling and help from an engineer, I was able to figure out what the problem was and how to fix it. This problem can occur with most/all e-bikes.While my fix won’t work for everyone or even most people, it might help point you in the right direction

Exclamation mark error

The main problem with the support I received was that it was never explained to me what the error was, so it felt like I was just doing random things with the bike.

Some googling shows that an exclamation point pops up when you app breaks. This indicates that the power to the motor is cut off due to the brake.

Once I realized that, everything made more sense.

fix exclamation mark bug

If the exclamation mark stays on, it means the bike thinks the brakes are engaged.

None of these worked for me, but possible solutions:

• Make sure the level is fully released, push it out to make sure it is not stuck
• Check that the magnet is not slipping on the brake lever
• Check all connections around the brake lever to make sure nothing is loose
• Engineers recommend inserting a piece of metal into the hole where the brake lever is.This is one of the things that makes me very confused about what I’m doing and why

None of these fixes worked for me. Instead, I removed the battery and turned the bike on to where all the wires were connected and checked all the connections.

With the help of an engineer, and after a lot of trial and error, I found the cable that caused the exclamation mark. Unplugging it, unplugging it, and plugging it back in again caused the problem.

I also found another cable of the same color that wasn’t plugged in, so I tried swapping them. I sloppily reinstalled the battery, rode the bike in my garden and everything magically worked. I’m concerned that I’ve disabled some security features, but app interrupts show the exclamation mark and turn off the motors, as it should.

For my bike, the cable in question is the yellow and black cable that has a black push connector with two pins in it. There are three cables, two are connected and one is disconnected and tied.

Unfortunately, it’s very difficult and frustrating to open up the bike, mess with cables and try to put everything back together. The cables are packed tightly and it takes a long time to pack everything far enough that I can screw the battery connectors.

Also, when I pull out the wire, the key and locking mechanism pop out. Without this return, the battery will not snap into place properly.