One: When the power supply of the control component of the electric vehicle brush controller is abnormal
1. The internal power supply of the electric vehicle controller generally adopts three-terminal voltage-stabilized integrated circuits, generally 7805, 7806, 7812, 7815 three-terminal voltage-stabilized integrated circuits, and their output voltages are 5V, 6V, 12V and 15V, respectively.
2. Set the multimeter to the DC voltage +20V (DC) position, lean the black and red test leads of the multimeter against the black line and red line of the handle, and observe whether the reading of the multimeter matches the nominal voltage, and the difference between their upper and lower voltages It should not exceed 0.2V.
3. Otherwise, it indicates that the internal power supply of the controller is faulty. Generally, the brushed controller can eliminate the fault by replacing the three-terminal regulator IC. 
Two: When the brushless controller of the electric vehicle is out of phase
The faults of the power supply and brake handle of the brushless controller of the electric vehicle can be preliminarily eliminated by referring to the troubleshooting method of the brushed controller. For the brushless controller, there are also unique fault phenomena, such as lack of phase. The phase loss phenomenon of the electric vehicle brushless controller can be divided into the main phase loss phase and the Hall phase loss phase.
1. The detection method of the lack of the main phase can refer to the troubleshooting method of the electric vehicle brushed controller to detect whether the MOS tube has broken down. The breakdown of the MOS tube of the brushless controller is generally a pair of MOS tubes above and below a certain phase Break down at the same time, make sure to replace at the same time when replacing. Check the measuring point.
2. The Hall phase loss of the brushless controller of the electric vehicle is that the controller cannot recognize the Hall signal of the motor.