Testing speed sensor with a DMM
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With the power off, remove the cover to expose the control board.
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Locate the speed sensor by the flywheel.
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Follow the speed sensor wires and to the main control board.
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Unplug the cable.
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Insert DMM into the speed sensor connector being held in hand and not on the board.
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Rotate the belt until the DMM shows an Ohm change. It should read close to 0 ohms when the magnet on the flywheel passes in front of the speed sensor. After it passes, it should go back to reading 'OL'.
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If the above happens, the speed sensor is good.
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If the above fails, then replace the sensor.
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When installing the new sensor, it should be about 3/4" away from the flywheel. Placing it too far away will prevent it from working.
Testing speed sensor with LEDs
1) With the power off, remove the cover to expose the control board.
2) Locate the LED that corresponds with the speed sensor. These can be labeled one of many ways including 'Speed', 'PWM' or 'Sensor'.
3) Power the unit after it is safe to do so.
4) Rotate the belt and look for an LED to flash. This will happen when the magnet on the flywheel passes in front of the speed sensor.
5) If the LED flashes, then the speed sensor is good.
6) If the LED never flashes, then replace the speed sensor.
7) If you are still unsure, then please follow our guide 'Testing speed sensor with a DMM'.