Display works but no pedal assist

If the display is on but you get no help, the bike is often being told not to assist. That's usually a setting, a sensor or a brake cut-off, not the motor.

Check first

1. Make sure an assist level is selected. Level zero or an off mode gives no help. On Shimano, if the switch flashes blue or an arrow shows, a short press of assist up returns you to the previous mode (Shimano STEPS FAQ).
2. Check the battery level. Velotric says a low charge can reduce or cut assist (Velotric troubleshooting).
3. Squeeze and release both brake levers. A lever that stays slightly pulled keeps the brake cut-off active (Velotric troubleshooting).
4. Look at the speed sensor and the magnet on the wheel or rotor. If the controller can't read your speed, it may shut off pedal assist (Himiway speed sensor). Wipe both clean and make sure the magnet passes the sensor's mark. Lift the wheel and spin it to see if the display reads a speed (Himiway speed sensor).
5. Clean mud and debris from the pedal sensor area near the crank (Velotric troubleshooting).
6. Look for an error code. A speed sensor fault is code 21 on Bafang displays, for example (Bafang C271 manual). See error codes.
7. Turn the bike off, reseat the battery and plugs you can reach, and start again (Velotric troubleshooting).
8. If you've been climbing or hauling a load, let the motor and battery cool (Velotric troubleshooting).

If the throttle works but pedal assist doesn't

Then the motor and battery are working, and the fault is more likely the pedal or speed sensor side. Cadence sensors use magnets near the crank to sense that you're pedaling. Torque sensors measure how hard you pedal, and sit in the bottom bracket, rear dropout or crankset (Velotric pedal assist 101). Velotric suggests cleaning a dirty magnet ring but leaving adjustment to a shop unless your manual covers it (Velotric troubleshooting). Torque sensor faults need a shop.

If neither works

See motor cuts out and won't turn on.

Get it checked if

• Assist keeps cutting out at a normal charge level, or the motor keeps driving while you brake (Velotric troubleshooting).
• A sensor cable is cut or pinched, or the code returns after a restart.

Sources

• Shimano STEPS FAQ, Shimano
• Electric bike troubleshooting guide, Velotric
• Ebike not reading speed, Himiway
• C271 display user manual, Bafang
• Pedal assist 101, Velotric

Stuck after these checks? Find a shop near you.