Precor Error Code 23

Error Description

Error 23, Motor Pulses Missing after Start-Up - Indication that the speed sensor signal was lost while the unit was in operation.

Probable Cause

1. The line of sight between the speed sensor and the speed sensor target is obstructed.
2. An incorrect gap between the speed sensor and the speed sensor target.
3. Incorrect adjustment of the speed sensor potentiometer (when equipped).
4. Intermittent connection of speed sensor or drive motor wiring.
5. Badly worn drive motor brushes not able to make proper contact with drive motor commutator.
6. Faulty lower PCA.
7. Faulty interconnect cable between upper and lower PCA.
8. Faulty upper PCA.

Corrective Action

1. Using a static-safe vacuum cleaner, carefully vacuum out the drive motor compartment.  Be sure to thoroughly clean the area between the speed sensor and the speed sensor target.
2. Inspect the gap of the speed sensor to the speed sensor target.  The proper gap is 3/16" and the speed sensor photo eye should be aimed at the larger portion of the target's wedge-shaped section.  If the unit has a magnetic speed sensor, the gap between the end of the sensor and the flywheel tooth needs to be 3/16".
3. Locate the speed sensor potentiometer (when equipped) on the lower PCA.  Set the speed sensor potentiometer to mid-range.  Start the treadmill and increase speed to 6 mph.  Carefully adjust the speed sensor potentiometer until the treadmill is operating the smoothest.  Increase the speed to full speed and again adjust the speed sensor potentiometer until the treadmill is operating the smoothest.  These two adjustments are typically small and are generally only a matter of fine-tuning.
4. Test all wiring and wire connections of the speed sensor and drive motor.  Replace or repair necessary wire connections or wiring.
5. Inspect and replace drive motor brushes if necessary.
6. Determine if the lower PCA is bad by swapping with a known good lower PCA.
7. Determine if the interconnect cable is bad by swapping with a know good cable.
8. Determine if the upper PCA is bad by swapping with a know good upper PCA.