Friday, March 15, 2013


                                                   Error 43 - Zero Switch not Found
  The C944 and several versions of C96X used a lift position identification system that did not
utilize a potentiometer. Instead, it utilized a switch that would be physically actuated by the lift when the lift was in the zero incline position. A revolution sensor counted lifted motor revolutions to determine subsequent lift positions. In addition two limit switches where used to remove power from the lift motor if the lift moved outside of it’s normal range. When the unit was powered up the lift would start to hunt for the zero switch. It would first go up 4% (maximum lowest physical position was -3%) if it did not find the zero switch or it hit the upper limit switch, it would then go down until did find the zero switch. When the zero switch was located it would stop, the system would then know its physical position and be prepared to monitor the revolution sensor. If during this power up procedure the zero switch was not found an error 43 would be displayed.
Possible Causes
1. The lift position actuator does not physically operate the zero switch.
2. The lower PCA is bad.
3. The zero switch is bad.
Possible Remedies
1. There are several physical problems related to the lift platform mounting or the plate the zero
witch is mounted on that can cause the actuator knob to miss the zero switch as it moves
past. Repair the lift platform mounting, repair or replace the lift switch mounting plate as
2. The lower PCA provides a 5 VDC power source for the zero switch. You should measure 5
VDC across the zero switch when the zero switch is activated. If the reading is significantly
low, remove both wires from the zero switch and repeat the measurement across the wires
removed from the zero switch. If the reading is still significantly low, verify the zero switch
wiring. If the wiring is intact and correctly connected, replace the lower PCA.
3. Move the lift to position where the zero is switch is not activated and remove power from the
treadmill. Remove both leads from the zero switch and measure the zero switch with an
ohmmeter. The zero switch should read very near 0 ohms. While measuring the zero switch
with the ohmmeter, activate the switch by hand, the reading should change to infinite (open).
If either of the above readings are significantly incorrect, replace the zero switch.