John Deere 127 – LC1 (and Left Power Module 1): Feeder House Position Sensor Voltage Out of Range

The voltage signal from the feeder house position sensor is outside its expected operational range. The control unit logs this fault when the sensor's voltage is either too high (greater than 4.5 VDC) or too low (less than 0.5 VDC). This indicates an issue with the sensor itself, its associated wiring circuit, or the control unit reading the signal.

• 9450
• 9550
• 9650
• 9560 STS
• 9660 STS
• 9760 STS
• 9860 STS
• 9470 STS
• 9570 STS
• 9670 STS
• 9770 STS
• 9870 STS
• S560
• S690

1. 1

   Use the machine's onboard diagnostic system to confirm the active or stored fault codes, noting the specific controller (e.g., LC1) and the exact FMI.

2. 2

   Visually inspect the feeder house position sensor and its wiring harness for cracked or frayed wires, loose connections, or corrosion on the connector pins.

3. 3

   Inspect the mechanical linkage connected to the sensor, including the sensor lever, tie rod, and stem, for damage or excessive wear.

4. 4

   Use a multimeter to test the voltage at the sensor connector to verify if it is outside the acceptable 0.5 VDC to 4.5 VDC range.

1. 1

   Confirm the fault

   Verify the fault code through the machine's diagnostic display.

2. 2

   Inspect and secure connections

   Ensure the sensor's electrical connector is clean and securely fastened. Inspect the wiring harness for damage and repair as needed.

3. 3

   Inspect mechanical linkage

   Check the sensor's operating lever and tie rod for proper installation and movement.

4. 4

   Test the circuit

   Test the sensor's power, ground, and signal circuits to isolate the problem to the sensor, the wiring, or the control unit.

5. 5

   Replace faulty components

   If the sensor is identified as the faulty component, replace it. If the mechanical linkage is bent or broken, it must also be replaced.

6. 6

   Calibrate the system

   After replacing the sensor or related components, perform a header or feeder house calibration procedure through the combine's display to ensure accurate position data.