What does code 22 mean?

Error 22 - No Motor Pulses at Start Up
Description
Error 22 indicates that the drive motor (running belt) has been instructed to start, by either
manual or program control, and the monitoring system has not received any response from the
speed sensing system indicating that the drive motor has started.
Possible Causes
1. The treadmill utilizes an optical (infrared) speed sensor and the line of sight between the
speed sensor and the speed sensor target is obstructed.
2. Drive motor brushes are bad.
3. The speed sensor position relative to the speed sensor target is incorrect.
4. The speed sensor potentiometer adjustment is incorrect (when equipped).
5. The speed sensor is inoperative.
6. The lower PCA is bad.
7. The lower PCA to upper PCA interconnect cable is bad.
8. The upper PCA is bad