John Deere 569.03 – CCU: Rear Differential Lock Solenoid Supply Voltage High

The control unit has detected a malfunction in the rear differential lock solenoid driver or its circuit. The system is seeing a voltage reading that is higher than the expected normal range, which typically points to a short to a voltage source, an open circuit, or an over-temperature condition in the solenoid circuit.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R
• 9230
• 9330
• 9430
• 9530
• 9630
• 5085M
• 5115M
• 5055E
• 5075E
• 7185J
• 7195J
• 7205J
• 7210J
• 7225J
• 210LJ
• 210K EP
• 310J
• 310G

1. 1

   Cycle the differential lock switch on and off to see if the code clears or resets itself.

2. 2

   Locate the Rear Differential Lock Solenoid (designated as Y502 in wiring diagrams).

3. 3

   Visually inspect the wiring harness running from the CCU to the Y502 solenoid for pinched wires, chafing against the chassis, or melted insulation.

4. 4

   Disconnect the solenoid and use a multimeter to check the signal wire for unexpected voltage (indicating a short to power).

5. 5

   Measure the internal resistance of the solenoid coil to see if it is out of specification (indicating an open or internally shorted coil).

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the battery ground to prevent electrical spikes during repair.

2. 2

   Access the Solenoid

   Locate the Rear Differential Lock Solenoid (Y502) on the rear axle or transmission housing (location varies slightly depending on whether the machine has a PowrQuad, e23, or IVT transmission).

3. 3

   Repair Wiring

   If the diagnostic tests revealed a short to power in the harness, repair the damaged section of the wire and replace any compromised loom.

4. 4

   Replace the Solenoid

   If the wiring tests good but the solenoid coil is internally shorted or open, remove the retaining hardware holding the solenoid valve in place and extract the faulty solenoid.

5. 5

   Install New Part

   Lubricate the O-rings on the new solenoid with clean hydraulic/transmission fluid. Insert the new solenoid and torque the retaining hardware to OEM specifications.

6. 6

   Reconnect and Clear

   Reconnect the electrical harness to the solenoid. Reconnect the battery, turn the key on, and use the monitor or Service ADVISOR tool to clear the CCU 000569.03 code.

7. 7

   Test Operation

   Start the machine and engage the rear differential lock to ensure the code does not return and the lock engages properly.