John Deere 521421.31 – HCC: Rear Hitch Encoder Lower Data Fault / Rear Hitch Encoder Increase Data Fault

The Hitch Control Controller is receiving invalid, erratic, or out-of-range data from the rear hitch position encoder when the hitch is being commanded to move (lower or increase).

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8R Series
• 8RT Series
• 8RX Series
• 8245R
• 8270R
• 8295R
• 8320R
• 8345R
• 8370R
• 8400R
• 9RT Series
• 9470RT
• 9520RT
• 9570RT

1. 1

   Check for accompanying codes such as HCC 001873.11 (HCC Calibration Fault/Rear Hitch Position Sensor Circuit) or HCC 521421.09 (Rear Hitch Encoder Lower Message Missing)

2. 2

   Inspect the wiring harness and connectors between the HCC and the Rear Hitch Encoder for rubbed wires, pinched harnesses near the rear rockshaft, or corrosion inside the encoder connector

3. 3

   Verify that the rear hitch encoder linkage is physically intact, properly mounted to the rockshaft, and not binding or bent

1. 1

   Resolve Wiring Issues

   If the diagnostic checks reveal high resistance, shorts to ground, or broken wires in the encoder circuit, repair the wiring harness or replace the connector pigtail.

2. 2

   Replace the Encoder

   If the wiring and physical linkage are intact but the data fault persists, the internal sensor of the Rear Hitch Encoder has failed and must be replaced.

3. 3

   Recalibrate the HCC

   After replacing the encoder or repairing the wiring, you must perform a Rear Hitch Calibration. This is typically done via the tractor's CommandCenter display or using John Deere Service ADVISOR to teach the HCC the new minimum and maximum voltage/data limits of the hitch travel.

4. 4

   Clear Codes

   Clear the stored HCC 521421.31 code and test the hitch operation through its full range of motion.