John Deere SCO523931.05 – SCO: SCV V Extend Solenoid Circuit Current Problem

The Secondary Hydraulic Control Unit (SCO) has detected low current in the electrical circuit for the SCV V extend solenoid (component designator Y840). This indicates that the electrical current being drawn by the solenoid that activates the 'extend' function of the fifth Selective Control Valve is below the expected range. This condition can be caused by a faulty solenoid, a poor electrical connection, or a damaged wire.

• 9230
• 9330
• 9430
• 9530
• 9630
• 7720
• 7820
• 7920
• 7630
• 7730
• 7830
• 7930
• 8130
• 8230
• 8330
• 8430
• 8530

1. 1

   Perform a visual inspection of the SCV V extend solenoid, its wiring harness, and connectors for physical damage, corrosion, or debris.

2. 2

   Inspect the area around the batteries and alternator for any visible electrical issues.

3. 3

   Check the relevant hydraulic system fuses (Fuse F29 for 9030 series; Fuses F12, F24, and F51 for 7030 series).

4. 4

   Restart the tractor to determine if the fault is an intermittent communication glitch.

5. 5

   Test the solenoid coil resistance with a multimeter. A normal 12V system reading is 2.4 to 2.8 ohms. Infinite resistance indicates an open circuit, while near-zero indicates a short.

6. 6

   Inspect the wiring harness between the SCO controller and the solenoid for continuity, breaks, or shorts to the chassis.

1. 1

   Relieve hydraulic pressure

   Before beginning any work on the hydraulic system, relieve all hydraulic pressure to avoid serious injury from high-pressure fluid.

2. 2

   Locate and disconnect solenoid

   Identify the SCV V extend solenoid located on the SCV stack and disconnect its electrical connector.

3. 3

   Remove the solenoid

   Unscrew the solenoid from the valve body. Be prepared for some residual hydraulic fluid to leak out during removal.

4. 4

   Install the new solenoid

   Screw the new solenoid into place and tighten it to the manufacturer's specified torque.

5. 5

   Reconnect and test

   Reconnect the electrical connector to the new solenoid. Start the tractor and operate the SCV V extend function to ensure it is working correctly and the fault code does not reappear.

6. 6

   Check for leaks

   With the system pressurized, carefully inspect the new solenoid and valve block area for any signs of hydraulic fluid leakage.