Thursday, March 14, 2013


                                      Error 23 - Motor Pulses Missing after Start Up
Error 23 indicates that the speed sensor signal was lost while the treadmill was in operation.
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. The speed sensor position relative to the speed sensor target is incorrect.
3. The speed sensor potentiometer adjustment is incorrect.
4. The speed sensor or drive motor wiring has an intermittent connection.
5. The drive motor brushes are badly worn and not making sufficient contact with the drive
motor commutator
6. The lower PCA is bad.
7. The lower PCA to upper PCA interconnect cable is intermittent.
8. The upper PCA is bad
Possible Remedies
1. Carefully, vacuum out the drive motor compartment with a static safe vacuum cleaner. Pay
special attention to the area between the speed sensor and speed sensor target.
2. Adjust the speed sensor position so that the space between the speed sensor and the sped
sensor target is 3/16 inch and so that the speed sensor photo eye is aimed at the larger
portion of the targets wedge shaped section
3. Locate the speed sensor potentiometer on the lower PCA. Set the speed sensor
potentiometer at mid-range. Start the treadmill and increase the speed to 6 mile per hour.
Carefully adjust the speed sensor potentiometer to the point where the treadmill is operating
the smoothest. Increase the treadmills speed to full speed at repeat the previous adjustment.
These two adjustments are typically small and are usually only a matter of fine tuning.
4. Physically test all wiring and wire connections associated with the speed sensor and drive
motor. Replace or repair wiring and wire connections as appropriate.
5. Replace both drive motor brushes.
6. Substitute a known good lower PCA to determine if the lower PCA is bad.
7. Substitute a known good interconnect cable for the existing cable.
8. Substitute a known good upper PCA to determine if the upper PCA is bad.