ERROR 14
Segway-Ninebot
Segway-Ninebot Error 14: Throttle Hall Sensor Fault
Abnormal throttle accelerator signal voltage (outside 0.8V–4.2V Hall sensor bounds) or lever stuck during boot.
E-Scooter & E-Bike Fault Code Diagnostic Database
ENGINEER SUMMARY & QUICK ANSWER
Select your display fault code below for immediate 3-step multimeter & connector troubleshooting, ride-safety status, and exact OEM replacement part numbers across Segway-Ninebot, Xiaomi, Bosch, Bafang, and Shimano Steps.
ERROR 15
Segway-Ninebot
Segway-Ninebot Error 15: Electronic Brake Sensor Fault
Brake lever Hall sensor signal is out of calibration range or magnet has detached inside the brake handle.
ERROR 21
Segway-Ninebot
Segway-Ninebot Error 21: BMS Battery Communication Failure
Main ESC controller receives no serial telemetry data (TX/RX) from the Battery Management System (BMS).
ERR 503
Bosch eBike
Bosch eBike Error 503: Speed Sensor No Signal Detected
Drive unit senses motor torque and cadence while riding, but receives zero magnetic pulses from the rear wheel speed sensor.
ERR 504
Bosch eBike
Bosch eBike Error 504: Speed Signal Manipulation / Tampering Detected
Motor controller algorithm detected implausible ratio between wheel speed pulses and crank/motor RPM (tuning chip or magnet interference).
ERR 07
Bafang
Bafang Error 07: Over-Voltage Protection Fault (48V / 52V Battery Mismatch)
Controller input voltage exceeds upper firmware threshold (commonly 58.8V full 52V pack plugged into a 48V-only programmed controller).
ERR 30
Bafang
Bafang Error 30: Communication Fault (Display to Controller TX/RX Lost)
Display powers on from battery voltage, but serial UART/CAN communication lines (Green/Yellow wires) between display and motor controller are interrupted.
W013
Shimano Steps
Shimano Steps Error W013: Torque Sensor Initialization Incomplete
Drive unit torque strain gauge could not calibrate zero-offset during startup because rider foot pressure was resting on the pedal.
ERR 14/15
Xiaomi Scooter
Xiaomi Scooter Error 14 & 15: Throttle & Brake Hall Sensor Diagnostics
Xiaomi M365, Pro 2, 1S, 3, and 4 Pro throttle (14) or brake lever (15) Hall sensor voltage out of range.