Troubleshooting Pedal Assist on an E-Bike

If your bike is not pedal assisting, there are a few things that could be going on. Please note, this is for if you do not have pedal assist but do have throttle still. The problem parts could include:

  • Pedal Assist Sensor
  • Controller
  • LCD Display (very rare)

For a bike not pedal assisting, the first thing we want to check is the pedal assist sensor itself. The sensor works with 2 main parts: the sensor itself and the magnet wheel. What can commonly happen is the magnet wheel can slide on the axel and get too far from the sensor. It should be right against the sensor. So look at the crank of your bike and check to see the positioning of the magnet wheel and if it is far from the frame of the bike, just slide/push it back into place. This should solve most of the pedal assist issues.

If the magnet wheel is already close to the sensor or the pedal assist did not come back after moving it closer, then there is something else going on. The next thing we would check is to see if the pedal assist sensor light is turning on or not. Right next to the frame near the magnet ring, you will see a little silver ring with a box on it. This box has a little red light that turns on when there is power to it. If this light is not on or does not turn on when the pedals move, then there is no power going to the pedal assist sensor, or the sensor is broken.

From here, your best option is to replace the pedal assist sensor. Similar to the LCD Display, there is not much extra testing that can be done except plug a new one in the end and see if it works. If it works, then a pedal assist sensor is needed. If it still does not work, then a new controller is needed.

Here's a high-level overview of how pedal assist works on an eBike. 

Everything DIY E-Bike Repairs

Homepage: eBike Repair Guide

eBike Repair Basics & Assembly

eBike Brake System Service Guide

eBike Drivetrain Service Guide

eBike Wheels & Tire Guide

eBike Electric Repair Guide

Miscellaneous eBike Service Guide