1. E1 - Means the safety key is not properly inserted or the motor control board is faulty.
2. E2 - Indicates the speed sensor signal is not being received.
3. E3 - Indicates the incline motor signal is not being received.
4. E4 - Points to an issue with the motor control board which may need to be replaced.
5. E5 - Indicates a lack of communication between the motor control board and display console.
6. E6 - Indicates an over-current protection issue， which could be caused by a short circuit or excessive load on the motor.
7. E7 - Points to a calibration error in the incline system， which may require re-calibration.
8. E8 - Indicates an error in the speed sensor calibration， which may also require re-calibration.
9. E9 - Indicates a problem with the lower control board， which may need to be replaced.
10. E10 - Indicates an error in the incline sensor calibration， which may require re-calibration.
11. E11 - Indicates a problem with the motor control board， which may need to be replaced.
12. E12 - Indicates an error with the incline motor that may require replacement.
13. E13 - Indicates a problem with the console.
14. E14 - Points to an error with the incline motor that may require repair or replacement.
15. E15 - Indicates a problem with the console.
16. E16 - Indicates a problem with the speed sensor， which may need to be replaced.
17. E17 - Points to an error with the incline motor that may require repair or replacement.
18. E18 - Indicates a problem with the console.
19. E19 - Points to an error with the incline motor that may require repair or replacement.
20. E20 - Indicates an error with the speed sensor calibration， which may require re-calibration.
（完）
