John Deere 000569.05 – CCU: Rear Differential Lock Solenoid Circuit Fault

The Chassis Control Unit (CCU) has detected a malfunction in the electrical circuit of the rear differential lock solenoid. This is typically caused by an open circuit, a short circuit, or an over-temperature condition in the solenoid's driver circuit. As a result, the system degrades its function, meaning the rear differential lock may fail to engage or disengage correctly.

• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 5115ML
• 6010
• 6020
• 6110
• 6120
• 6210
• 6220
• 6300
• 6310
• 6320
• 6410
• 6420
• 6500
• 7210
• 7220
• 7410
• 7510
• 7610
• 7710
• 7720
• 7810
• 7820
• 7920
• 7930
• 8100
• 8200
• 8300
• 8400
• 9100
• 9120
• 9200
• 9220
• 9230
• 9300
• 9320
• 9330
• 9400
• 9410R
• 9420
• 9430

1. 1

   Cycle the differential lock switch and restart the tractor to see if the code clears (checks for a temporary communication glitch)

2. 2

   Inspect the mechanical linkage, engagement rod, and actuator connected to the differential lock for damage, excessive wear, or loose connections

3. 3

   Examine the wiring harness leading to the differential lock solenoid (often located in front of the right-hand three-point lift cylinder) for chafed or broken wires

4. 4

   Check the electrical connector at the solenoid to ensure it is clean, secure, and free of corrosion

5. 5

   Perform a functional test: engage the differential lock at low RPM and listen for unusual noises (grinding/clicking indicates internal mechanical issues)

6. 6

   Safely lift the rear of the tractor so both wheels are off the ground and engage the lock; both wheels should rotate together

7. 7

   Test the solenoid's coil for continuity using a multimeter (a functional solenoid typically reads between 10-12 ohms)

8. 8

   Check for voltage at the solenoid connector using a test light or by back-probing the connector while it is connected and the switch is activated (the controller may only send a test voltage of around 8 volts and will shut off the circuit if the solenoid is unplugged)

9. 9

   Ensure the hydraulic/transmission fluid is at the correct level as specified in the operator's manual

10. 10

    If electrical and mechanical checks pass, perform a hydraulic pressure test at the differential lock test port to check for low pressure (indicates a problem with the hydraulic pump or the valve itself)

1. 1

   Safety First

   Ensure the tractor is on a level surface, the engine is off, and the parking brake is engaged. It is also advisable to disconnect the battery.

2. 2

   Locate the Solenoid

   The differential lock solenoid is typically located on the rear differential housing.

3. 3

   Clean the Area

   Thoroughly clean the area around the solenoid to prevent dirt and debris from entering the hydraulic system when the solenoid is removed.

4. 4

   Disconnect Electrical Connector

   Carefully disconnect the electrical connector from the solenoid.

5. 5

   Remove the Solenoid

   The solenoid is usually held in place by bolts. Remove these bolts and carefully extract the solenoid valve from its housing. Be prepared for some hydraulic fluid to leak out.

6. 6

   Install the New Solenoid

   Ensure the new solenoid is the correct part for your tractor model. Lubricate the O-rings on the new solenoid with clean hydraulic fluid. Carefully insert the new solenoid into the housing and tighten the retaining bolts to the manufacturer's specified torque.

7. 7

   Reconnect and Test

   Reconnect the electrical connector. Reconnect the battery if it was disconnected. Start the tractor and check for any hydraulic leaks around the new solenoid. Test the operation of the differential lock to ensure it engages and disengages correctly, and check if the fault code has cleared.