When do I need to replace the Xiaomi Electric Scooter Controller (Controller)?

The controller of your Xiaomi electric scooter is the essential part that controls the motor, battery and other systems. Here are the main signs that the controller may need to be replaced:

1. Specific Error Codes:

   Engine Problems (e.g. Error 18): If your Xiaomi scooter shows an error related to the engine (e.g. Error 18), be sure to check the Hall sensors and their wiring first. If they are fine but the error persists, the problem often lies in the controller itself.
   Controller Overheating/Temperature Sensor Fault (Error 40): the Error 40 error usually indicates a failure of the temperature sensor on the controller’s main board or overheating of the controller itself due to internal problems. In this case, replacing the controller is a very likely solution.
   Battery Temperature Sensor Problems(e.g. Error 39): although less common, this error may be controller related.
   Other Power/System Errors: if the scooter shows other errors related to the power supply or overall system performance and other parts (battery, wires) are in good working order, the controller may be at fault. Other error messages can be found here>>

2. The scooter doesn’t start or switches off unexpectedly:

   Total Inactivity (“Dead”): If the scooter is completely unresponsive (does not turn on, does not move) even though the battery is charged, the fuse (if any) is intact, and all the main connections are in order, there is a very high probability that the controller is defective.
   Auto-shutdown: switches off unexpectedly, not due to low battery or overheating.
   Self-starting: the scooter starts itself shortly after the scooter is switched off, if the dashboard button is not pressed this is usually a controller problem.
   Unable to switch off: If the scooter cannot be switched off, it may also be a problem with the controller.

3. Faulty/unstable scooter performance (when other parts are checked):

   Driving Problems:
   Driving is uneven, jerky (not related to accelerator, Hall sensors or mechanical faults).
   Brakes itself.
   Speed limited for no apparent reason.

4. Physical Damage or Modifications to the Controller:

   External Damage: clearly visible faults (cracks, fractures, burnt components, damaged connections).
   Water ingress: if water has entered the controller.
   Unsuccessful Software Change: attempts to independently change (“chip”) the controller software.