John Deere 520529.17 – Front Chassis Module (SCO): Loader Boom Position Sensor Issue

The system has detected an issue with the signal coming from the front loader boom position sensor. Related fault codes (such as 520529.13, 520529.14, and 520529.16) indicate that the sensor may have lost calibration, or the voltage value is reading out of the expected range (too high/too low).

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R

1. 1

   Inspect the loader boom position sensor (typically a rotary Hall Effect sensor mounted on the loader boom pivot) for physical damage, debris, or loose mounting hardware.

2. 2

   Check the 3-wire sensor pigtail and the main harness connecting to the Front Chassis Module (SCO). Look for chafed wires, shorts to ground, or corrosion in the connector pins.

3. 3

   Verify that the sensor is receiving a steady 5V reference signal from the SCO module.

4. 4

   Attempt to perform the 'Front Loader Boom Position Sensor Calibration' via the tractor's command center/monitor as a loss of calibration is the most common cause.

1. 1

   Park and Secure

   Park the tractor on a level surface, lower the loader boom to the ground (if possible) to relieve hydraulic pressure, and turn off the engine.

2. 2

   Inspect/Clean

   Disconnect the boom position sensor connector. Clean the contacts with electrical contact cleaner and apply dielectric grease. Reconnect and test.

3. 3

   Recalibrate

   Turn the key to the ON position. Access the tractor's diagnostic/calibration menu and run the Front Loader Boom Position Sensor Calibration procedure.

4. 4

   Replace Sensor

   If the calibration fails, or if a multimeter confirms the sensor has an internal open/short (or is not returning a smooth variable voltage as the boom moves), the sensor must be replaced.

5. 5

   Install New Sensor

   Unbolt the faulty sensor from the loader boom pivot point. Install the new sensor, ensuring the rotary linkage/pin is correctly aligned with the boom's pivot path.

6. 6

   Final Calibration

   A new sensor must be calibrated after installation for the SCO module to learn the new minimum and maximum voltage limits corresponding to the boom's physical travel limits. Clear the 520529.17 fault code.