John Deere SCO523931.06 – SCO or SCU: SCV V Extend Solenoid Circuit Current High

The Secondary Hydraulic Control Unit (SCO) or the Selective Control Unit (SCU) has detected an excessive electrical current draw in the circuit for the solenoid that controls the extend function of the fifth Selective Control Valve (SCV). This condition can lead to improper operation of the hydraulic function controlled by this valve.

• 9230
• 9330
• 9430
• 9530
• 9630
• 9430T
• 9530T
• 9630T
• 9530 Scraper
• 9630 Scraper
• 8130
• 8230
• 8330
• 8430
• 8530
• 8230T
• 8330T
• 8430T
• 7720
• 7820
• 7920
• 7630
• 7730
• 7830
• 7930
• 9410R
• 9460R
• 9460RT
• 9510R
• 9510RT
• 9560R
• 9560RT

1. 1

   Visually inspect the wiring harness and connectors associated with SCV V for any signs of damage, such as chafing, melting, or corrosion. Also, check the area around the batteries and alternator for any visible issues.

2. 2

   Inspect the relevant fuses for the hydraulic system. Specifically, fuse F29 has been mentioned in relation to SCO supply voltage issues.

3. 3

   Test the resistance of the suspect SCV V extend solenoid and compare it to an identical, functioning solenoid on the same machine. A general test suggests 1.5 to 3.5 ohms, while a forum suggests 4.3 to 5.5 ohms. A significantly lower reading could indicate a short circuit.

4. 4

   Observe the hydraulic operation. If only one SCV is surging, it often points to a faulty solenoid within that SCV. If all SCVs are surging, the problem may lie with the main hydraulic pump control valve.

1. 1

   Relieve hydraulic pressure

   Before starting any repairs, relieve any pressure in the hydraulic system.

2. 2

   Access the SCV

   Locate the problematic SCV stack. It may be necessary to remove covers to access the solenoids.

3. 3

   Disconnect wiring

   Carefully disconnect the two wiring connectors from the SCV controller board. These can be delicate, and a hook tool may be useful for releasing the clips.

4. 4

   Remove the solenoid cover

   Remove the bolts holding the solenoid cover in place. This cover also secures the solenoid. Be gentle during removal as the bolts may be rusted.

5. 5

   Remove the solenoid

   The solenoid should pop out of its housing.

6. 6

   Inspect for debris

   Check inside the valve for any broken pieces from the old solenoid. A small plastic piece on the end of the solenoid can sometimes break off and must be retrieved with a pick.

7. 7

   Install the new solenoid

   Install the new solenoid into the valve body.

8. 8

   Reassemble

   Reinstall the solenoid cover, ensuring the new bolts that often come with the new solenoid are used. Reconnect the wiring connectors to the SCV controller board.

9. 9

   Test operation

   After reassembly, start the tractor and test the function of the repaired SCV.