Knowledge base
Brake switch
Possible causes
- Brake lever does not fully return
- Brake switch/magnet misaligned or faulty
- Brake switch cable damaged
Safe test steps
- Lever return, magnet/sensor position.
- Unplug switches one at a time for diagnosis (reconnect afterwards!).
Workshop reference values
- Brake switches are normally-open, normally-closed or Hall type – measure per the manufacturer diagram.
Repair approach
- Adjust or replace the brake lever/switch.
Tools needed
- Digital multimeter (CAT III, fused inputs)
- Basic hand tools, insulated screwdrivers
Safety
- Never permanently disable the brake motor cut-off.
Related verified fault codes
| Code | Meaning | Component | Reliability |
|---|---|---|---|
| Bafang 33 | Brake signal fault | Brake switch | Per manufacturer documentation |
| SW900 LCD 25 | Brake abnormality | Brake switch | Widely published – may differ by model/firmware |
| S866 LCD 25 | Brake abnormality | Brake switch | Widely published – may differ by model/firmware |
| Xiaomi 15 | Brake lever fault / not in zero position | Brake switch | Widely published – may differ by model/firmware |
| Segway-Ninebot 15 | Brake lever fault / not in zero position | Brake switch | Widely published – may differ by model/firmware |