John Deere 1873.31 – HCC: Rear Hitch System - Purge required / HCC Calibration Fault in the Rear Hitch Position Sensor Circuit

The system has lost its calibration or requires a hydraulic purge, which causes the position control of the rear hitch to be disabled. The controller cannot accurately determine the physical height of the hitch, triggering a restricted function state.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7185J
• 7210J
• 7200R
• 7215R
• 7230R
• 7310R
• 8130
• 8230
• 8330
• 8430
• 8530
• 8225R
• 8245R
• 8310RT
• 8360RT
• 8400R
• 9230
• 9330
• 9430
• 9530
• 9630
• 9470RT
• 9520RT
• 9570RT
• 5085M
• 5115ML

1. 1

   Cycle the hitch fully up and down three times to attempt a system recovery/purge

2. 2

   Cycle the tractor's key switch (power down completely, wait, and restart) to see if the code clears

3. 3

   Inspect the Rear Hitch Position Sensor and its wiring harness for physical damage, loose connector pins, or corrosion

4. 4

   Verify the sensor's output voltage using Service ADVISOR to ensure it is not reading out of range (e.g., below 0.25V or above 4.75V)

1. 1

   Prepare for Calibration

   Ensure the hitch is free to move through its full range of travel. Remove all implement hydraulic hoses.

2. 2

   Add Weight

   Install 300–500 lbs (136–226 kg) of weight on the rear hitch. (Note: If a quick coupler is installed, only 150–200 lbs is needed).

3. 3

   Run Calibration

   Connect John Deere Service ADVISOR. Navigate to the Hitch Control Unit (HCC/HCU) tab and select Address HCC 020 (Rear Hitch Calibration). Follow the interactive steps to calibrate the Maximum Raise Rate, Draft Sensor Voltage, and Raised/Lowered Position Sensor Voltages.

4. 4

   Replace Sensor (If Calibration Fails)

   If the calibration fails or the sensor is dead, locate the Rear Hitch Position Sensor on the rear rockshaft/lift arm assembly. Disconnect the harness, unbolt the sensor, and install the new unit.

5. 5

   Post-Repair Calibration

   A full HCC calibration via Service ADVISOR is mandatory after replacing the position sensor. The system will not function properly until the new sensor's parameters are learned.