John Deere 520256 – HV1: Rear Hitch Stepper Motor Issue

The control unit has detected a malfunction, communication failure, or unexpected position reading from the rear hitch stepper motor.

• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 5115ML

1. 1

   Power cycle the system by turning the key switch off and on, or restarting the engine to clear potential temporary software glitches or voltage drops.

2. 2

   Check for related fault codes, such as 520260.00 (Rear Hitch Stepper Motor High Amps) or 520255.19 (Internal CAN BUS Message Missing), which might pinpoint the issue.

3. 3

   Verify system voltage from the battery and alternator, as the HV1 module is highly sensitive to voltage drops.

4. 4

   Inspect the physical wiring harness and connectors running to the rear hitch stepper motor and the HV1 module for corrosion, moisture, or physical damage.

5. 5

   Cycle the external fender control buttons or the in-cab hitch lever to see if the system can re-establish the motor's position.

1. 1

   Disconnect Power

   Disconnect the negative battery cable before servicing electronic hydraulic valves.

2. 2

   Locate the Stepper Motor

   Locate the electric stepper motor mounted on the rear rockshaft control valve assembly at the rear of the tractor.

3. 3

   Remove the Faulty Motor

   Disconnect the electrical harness connector from the stepper motor. Unbolt the stepper motor from the hydraulic hitch valve block.

4. 4

   Install the New Motor

   Mount the replacement stepper motor to the valve block and torque the mounting bolts to OEM specifications. Reconnect the wiring harness.

5. 5

   Reconnect Power

   Reconnect the battery.

6. 6

   Calibrate the Hitch

   Calibrate the new stepper motor to the HV1 controller using John Deere Service ADVISOR or through the onboard diagnostic addresses (e.g., HCC 053, HCC 054, HCC 055) so it learns the deadbands for the raise and lower valves.

7. 7

   Clear Codes and Test

   Clear the stored 520256.00 code from the HV1 module and test the rear hitch through its full range of motion.