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.