John Deere 520531.07 – SCO: Loader Bucket Position Sensor Issue

This fault code indicates a malfunction, circuit fault, or calibration error with the sensor responsible for monitoring the tilt/curl angle of the front loader bucket. This sensor is critical for the tractor's Return-to-Position (RTP), Return-to-Dig, and electronic self-leveling functions.

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

1. 1

   Use a diagnostic tool (like John Deere Service ADVISOR, TEXA Off-Highway, or Jaltest) to verify if the code is active or stored, and monitor the live voltage/degree readings of the bucket position sensor

2. 2

   Thoroughly inspect all machine wiring along the loader frame (especially on the RH side) for pinch points when the boom is fully raised, which can cause direct power-to-ground or CAN circuit shorts

3. 3

   Check the physical linkages that actuate the sensor. Verify the gap on the bellcrank-to-loader control lever linkage yoke (specification is typically 1-2 mm / 0.04-0.08 in. when fully depressed in the BUCKET CURL position)

4. 4

   Inspect the sensor tube-to-actuator yoke and the return-to-dig switch for physical damage, bending, or debris interference

1. 1

   Position the machine

   Park the tractor on a flat, level surface. Lower the front loader bucket until it is flat on the ground and turn the engine OFF.

2. 2

   Replace the sensor

   If wiring is intact but the sensor has failed or lost its zero-reference, disconnect the electrical connector from the bucket position sensor. Remove the retaining hardware, swap in the new sensor, and reconnect the harness.

3. 3

   Perform mechanical adjustment

   Ensure the front loader bucket self-leveling linkage and return-to-dig switch are adjusted together. Adjust the bellcrank-to-loader control lever linkage yoke, followed by the sensor tube-to-actuator yoke.

4. 4

   Perform electronic calibration (CommandCenter)

   Start the tractor. Access the CommandCenter menu and press the selective control valve softkey, then select the front loader icon to open the Return-to-Position window. Set the bucket to the desired flat zero position and save it so that it registers as 0 degrees on the display.

5. 5

   Perform diagnostic tool calibration (Alternative)

   If using Service ADVISOR or an equivalent tool, navigate to MAIN MENU CALIBRATION -> CALIBRATION BOOM AND BUCKET and follow the on-screen prompts to calibrate the control valve threshold values and sensor limits.