E-Bike Brake Cutoff Sensors

In plain English

Most e-bikes have a sensor on each brake lever (or a small magnet sensor stuck to it) that tells the controller you're braking. It's a safety feature. A lever that doesn't fully return, a sensor that has slipped, or a damaged cable can make the motor cut out or not work at all. These sensors don't affect how hard the brakes stop.

Work from the top. Steps go from free and easy to shop jobs. Switch the bike off before touching any connector. Tick each step as you go. Your progress is saved on this device.

1. 1Check the brake levers spring backFree Squeeze and release each brake lever. Both should snap all the way back. A lever that stays slightly pulled keeps the motor switched off.
2. 2Switch on without touching the brakesFree Holding a brake while switching on can confuse some systems. Switch off, hands off the levers, and switch on.
3. 3Line up magnet sensorsEasy If a small sensor and magnet are stuck to the lever, check the magnet sits right next to the sensor when the lever is released. Re-stick it if it has slid.
4. 4Find a faulty brake sensorEasy Switch off. Follow the thin cable from each brake lever to its plug. Unplug one, switch on and test, then try the other. If the problem goes away with one unplugged, that sensor is faulty. Plug it back in and replace it, because the brake cutoff is a safety feature.
5. 5Replace a faulty sensorModerate Buy sensors with the same plug, and replace the faulty one. Never leave a sensor unplugged or bypassed.

Parts you might need

As an Amazon Associate I earn from qualifying purchases. These links go straight to Amazon.

Only buy a part if the free steps didn't fix it. Always match the voltage and connector type to your bike.

• Brake cutoff sensors

  Replaces a faulty brake sensor that keeps cutting motor power.

  Link coming soon

• Electrical contact cleaner spray

  Cleans dirt and corrosion from connector pins and battery contacts.

  Link coming soon