Precor Error Code 21
Error Code: 21 Manufacturer: Precor
Model: All Models
Error 21, Too many Consecutive Power Requests- The error 21 observes a treadmill's power bit reading when the treadmill was operating at speeds above 1 mph. Power bits indicate the relative time that the motor controller drive circuit is turned on. Power bits is an indication of the amount of power the load is demanding from the motor controller. Error 21 indicates that at a speed greater than 1 mph, an excessive amount of power is being demanded from the motor controller.
A badly worn deck and/or running belt can cause the error to appear when the unit is in use.
Badly worn drive motor brushes may not be making proper contact with the drive motor commutator causing the error to occur when the unit is in use. The unit may also slow down or become sluggish when the load or speed is increased.
A jumper may be required on the lower PCA if installed into a 120 VAC (Version 2) treadmill.
A leaky or shorted drive motor filter capacitor (on units equipped with SCR motor controller) could increase the current demand enough to cause the error.
A leaky or shorted drive motor inductor (on units equipped with SCR motor controller) could increase the current demand enough to cause the error.
The high power demand is caused by a shorted or de-magnetized drive motor.
Determine the amount of AC input current being drawn by the unit under no load and loaded conditions using a clamp on AC ammeter. The current displayed can be used to determine the condition of the deck and/or running belt. These same readings should be taken on a like unit, in good operating condition with a know good deck and running belt. The readings from the unit in good operationg condition can be used as the benchmark. Compare readings and replace* the deck and/or running belt if necessary. *Some units have a reversible deck. Be sure if the deck is being flipped or replaced, a new belt is installed on the new deck surface.*
Inspect and repalce both drive motor brushes if necessary.
Inspect the lower PCA (if unit is 120 VAC/ Version 2) for jumper. If jumper is not installed, error typically appears between 7 mph & 8 mph. Install jumper if necessary. CAUTION - DO NOT install jumper if unit is 240 VAC. Installing the jumper on a 240 VAC unit will casue the lower PCA to fail.
Measure the AC input current without a load using a clamp on AC ammeter. Electrically isolate the filter capacitor from the drive motor circuit. The drive motor leads need be kept intact so the drive motor will operate with the filter capacitor removed from the circuit. Re-measure the no load AC input. If the AC input current is significantly lower, replace the filter capacitor.
Measure the AC input current without a load using a clamp on AC ammeter. Electrically isolate the inductor from the drive motor circuit. The drive motor leads need be kept intact so the drive motor will operate with the inductor removed from the circuit. Re-measure the no load AC input. If the AC input current is significantly lower, replace the inductor.
Swap the existing drive motor with a known good drive motor.
Precor Error LS, Speed Sensor Signal Missing
1. Intermittent or open connection of the speed sensor (reed switch) wiring.
2. Reed switch is defective or has intermittent connection.
3. Drive motor brushes are bad.
4. Lower PCA is bad.
Inspect the speed sensor (reed switch) wiring for damage or poor connection to the lower PCA. Replace damaged wiring or reset connection as necessary.
Using an ohm meter, test the reed switch while rotating the drive pulley. The reed switch will close when the magnet passes in front of it.
Inspect the drive motor brushes and replace if necessary.
Test unit with a known good lower PCA. Replace lower PCA if nec
Precor Error Code 22
Error Code: 22
Model: All Models
Error 22, No Motor Pulses at Start Up - Error indicates that the display has sent a command for the drive motor to start, however, the speed sensor has not returned the signal acknowledging that the drive motor has started.
The line of sight between the speed sensor and the speed sensor target is obstructed.
Badly worn drive motor brushes.
Incorrect gap between the speed sensor and the speed sensor target.
Incorrect adjustment of the speed sensor potentiometer (when equipped).
Inoperative speed sensor.
Faulty lower PCA.
Faulty interconnect cable between upper and lower PCA.
Faulty upper PCA.
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.
Bady worn drive motor brushes cannot make proper contact with the motor commutator, therefore the drive motor will not start when voltage is applied. Inspect and replace drive motor brushes if necessary.
Inspect the gap of the speed sensor to the speed sensor target. Proper gap is 3/16" and the speed sensor photo eye should be aimed at the larger portion of the targets wedge shaped section. If unit has a magnetic speed sensor, the gap between the end of the sensor and the flywheel tooth needs to be 3/16".
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.
An inoperative speed sensor will allow the drive motor to start and run briefly before the error appears. If able to access the speed sensor wiring, measure the DC voltage between the speed sensor leads. Two of the leads will always read about 5 VDC. Two will toggle between 0 and 5 VDC as you slowly turn the speed sensor target. If both measurements are not seen, the speed sensor needs replaced. Some units have the speed sensor mounted on the lower PCA and the lower PCA needs replaced.
Determine if the lower PCA is bad by swapping with a known good lower PCA.
Determine if the interconnect cable is bad by swapping with a know good cable.
Determine if the upper PCA is bad by swapping with a know good upper PCA.
Treadmill's belt get slipped when the the belt expands due to the usage and wear and tear. In all teradmill's there is an option for tighten the belt. I have added here some videos related to the belt tightening of treadmills. so many makes of treadmills the have similar adjustment. it will help you a lot to adjust the belt of your treadmill. you need allen keys to adjust the screws. watch the video and do the same. If you need further assistance fell free to contact me through fixya.
1. A key is permanently depressed on the display.
2. An interface chip (IC) has failed in the upper PCA's keypad.
3. Liquid (cleaning solution or sweat) may be on the surface of a touch sensitive display.
Disconnect the keypad cable from the upper PCA. Reset power to the machine. If the Error 05 is eliminated, the keypad is the cause and should be replaced.
Disconnect the keypad cable from the upper PCA. Reset power to the machine. If the Error 05 still appears, the upper PCA* is the cause and should be replaced. *Upper PCA's most commonly do not come with software. Remove the software (chip) from the existing upper PCA prior to replacement and install into the new upper PCA.
Wipe away all liquid from the touch sensitive display. Reset power to the unit. If the Error 05 is eliminated, the liquid was the cause.
Adjusting Tension on a Treadmill Running Belt
It is necessary to properly tension a treadmill belt when it is replaced. After time, a belt can stretch and may begin to slip. When this happens, it is necessary to adjust the tension of the running belt to stop it from slipping. Manufacturers of treadmills generally agree on one of three procedures for how to tension a treadmill running belt.
This procedure works well for a previously installed belt that is now slipping.
Underside of belt should be free of any glazing/wax buildup.
Rollers must also be free of wax buildup.
Be sure belt tracking/centering is correct before proceeding.
The most popular speed for this adjustment is 2mph to 3mph.
Try to slow the belt by applying pressure with your foot against the belt movement while grasping the handrails. If the running belt slow, slips or stops (and the front roller does not) adjust BOTH adjustment bolts 1/4 turn clockwise. Test again and repeat adjustment if necessary.
This procedure works well when installing a new belt.
This procedure requires you to stretch the belt. Depending on the manufacturer*, this varies between .4 and .6 percent. A dial on the gauge or caliper will indicate the amount of stretch. *Consult the owner/service manual for proper tension.
If you are working on a previously tensioned belt you will need to release the tension before attaching the gauges or calipers.
Gauges or Calipers unavailable
Release the tension on the belt.
Using a yard stick or tape measure, place two marks on the left and right edges of the belt and deck 36 inches apart (or 50 inches if you prefer).
Adjust the left and right tensioning bolts until both sides measure 36 3/16 inches (or 50 1/4). This is equal to .5% of stretch.
Test for proper tracking and tension, adjust if necessary.
Procedure 2.3 - Accessing the User Parameter Program
This procedure allows you to change the following settings:
• Set Measurement Units
• Enable/Disable Password
• Set User Name
1. Plug the power cord into the wall outlet, then turn on the treadmill with the circuit breaker.
2. Press keys STOP,5,6,7,1 sequentially.
3. The display will momentarily read SELECT UNITS
4. The currently selected measurement unit will then be displayed.
5. Use the UP, DOWN arrow keys to toggle between U.S. STANDARD and METRIC.
6. Press the ENTER key to select the currently displayed measurement unit.
7. The display will momentarily read, PASSWORD
8. Use the UP, DOWN arrow keys to select either PASSWORD ENABLED or PASSWORD DISABLED
9. Press the STOP or ENTER key to exit the program.
Fuse is a dead end in this case. Is there belt movement with the LS error, where the belt moves for a few seconds then quits? If so, there may be a problem with the upper - contact Precor and have them look up bulletins on that model/SN. If no belt movement, then there is a problem with either motor or MCB, probably MCB.