Danger: High Voltage & Safety
Always disconnect the battery main power cable (XT30/XT60 red/black connector) before handling motherboard or motor cables to prevent permanent controller damage.
Required Parts & Tools
Have these ready before starting the repair. Clicking links supports our free guides.
Replacement Parts Needed
- Xiaomi M365 / Pro Main Controller (ESC)$25 - $45
The central ESC control board. Often needs replacement if error 18, 27, or 28 is triggered.
Tools Required
- Digital Multimeter$15 - $30
Used to check cell voltages, controller output voltages, and wire continuity.
- Metric Hex Screwdriver Set$8 - $12
For opening the bottom battery cover and steering tube screws.
How Xiaomi Communicates Error Codes
Xiaomi scooters display error codes in two ways: either directly on the LED screen (for Pro, 1S, Pro 2, Essential models) or via dashboard flashes and buzzer beeps (for older standard M365 models).
The beep system uses long beeps for tens and short beeps for single units. For example: beep—beep-beep-beep-beep translates to 1 long (10) + 4 short (4) = Error 14.
Complete Xiaomi M365 / Pro Error Code Table
| Code | Severity | Symptom & Component | Diagnostic / Action |
|---|---|---|---|
| 10 | Medium | Dashboard/BLE communication error | Check the 5-pin wire inside the stem connection. Replug the dashboard connection. |
| 11 | High | Motor Phase A current sensor failure | Requires motherboard inspection. Replace the controller ESC. |
| 12 | High | Motor Phase B current sensor failure | Requires motherboard inspection. Replace the controller ESC. |
| 13 | High | Motor Phase C current sensor failure | Requires motherboard inspection. Replace the controller ESC. |
| 14 | Medium | Throttle Hall sensor abnormal | Check throttle magnet position. Replug or replace throttle. |
| 15 | Medium | Brake Hall sensor abnormal | Check brake lever magnet alignment. Replug or replace brake lever. |
| 18 | High | Motor Hall sensor abnormal | Check the green, yellow, blue wires in the controller. Test Hall sensors inside motor. |
| 21 | Medium | BMS battery communication error | Check the thin data line (BMS to controller). The blue flashing light on BMS should flash. Check connection. |
| 22 | Medium | BMS password error | Restore original serial numbers or re-flash standard BMS firmware. |
| 23 | High | BMS default serial number error | The BMS serial number is non-standard. Flash matching serials. |
| 24 | High | System voltage abnormal | Check battery pack voltage using a voltmeter. Likely cell imbalance or incorrect charger. |
| 27 | High | Controller serial number error | ESC motherboard serial number is invalid. Re-flash original serial. |
| 28 | High | MOSFET gate driver chip fault | High-current MOSFETs blown. Replace the controller board. |
| 35 | High | Incorrect controller serial number | Similar to 27. Ensure the serial number matches hardware specifications. |
| 39 | Medium | Battery temperature abnormal | The battery is too cold (below 0°C) or hot (above 55°C). Let the scooter acclimatize. |
Blowing MOSFETs (Error 28)
Error 28 is extremely common on M365/Pro scooters that have ridden down long hills with a full battery. Kinetic energy recovery (KERS) pushes charge back into the battery. If the battery is full, the BMS shuts off, creating a voltage spike that blows the MOSFET gate drivers. The best fix is to replace the controller ESC.