John Deere 520531.03 – Front Chassis Module (SCO): Loader Bucket Position Sensor Signal Voltage High

The controller is receiving a voltage signal from the bucket position sensor that exceeds the maximum expected threshold (typically near or above 5.0 volts). This is almost always caused by an open ground circuit, a short to power (5V or 12V) on the signal wire, or an internal failure of the sensor itself.

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

1. 1

   Inspect the bucket position sensor and its wiring harness for physical damage, pinched wires, or stretched cables.

2. 2

   Disconnect the sensor and check the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   Using a multimeter, check for continuity to ground on the sensor's ground pin, as an open ground is the most common cause of a voltage high code.

4. 4

   With the sensor disconnected and the key ON, measure the voltage on the signal wire to check for a short to power (5V or 12V).

5. 5

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

1. 1

   Safely Park the Machine

   Lower the loader bucket flat to the ground, turn off the engine, and relieve hydraulic pressure.

2. 2

   Repair Wiring

   If the diagnostic checks revealed an open ground or a short to power, trace the harness back to the Front Chassis Module (SCO) and repair the damaged wire.

3. 3

   Replace the Sensor

   If wiring is good, disconnect the electrical connector from the bucket position sensor, remove the mounting bolts/hardware, install the new sensor, tighten the mounting hardware to OEM spec, and reconnect the electrical harness.

4. 4

   Perform Calibration

   Perform the 'Front Loader Bucket Position Sensor Calibration' via the tractor's cab display monitor or John Deere Service ADVISOR tool.

5. 5

   Clear Codes

   Clear the 520531.03 fault code and cycle the loader through its full range of motion to verify the repair.