Massey Ferguson A.11.2A – Electro-Hydraulic Control Module / Vehicle Control System: External Hydraulic Valve 1 Issue

Malfunction in the first Selective Control Valve (SCV 1) circuit, which controls the rear hydraulic remotes. The underlying condition is typically an electrical communication failure, a faulty unlock solenoid coil, or a hydraulic restriction (such as a blocked internal SCV filter) that prevents the valve from unlocking and operating properly.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714 through 7726S

1. 1

   Check Cab Indicators: Observe the SCV unlock button on the cab console. A flashing red light indicates the system is locked out due to an error code.

2. 2

   Manual Override Test: Attempt to operate the valve manually using the rear fender/window controls. If it works manually but not from the cab, the issue is isolated to the electrical controls or the unlock solenoid.

3. 3

   Inspect the SCV Filter: Check the small, thimble-sized filter located inside the SCV body. A blocked filter is a known cause of erratic electrical issues and valve lockouts.

4. 4

   Electrical Testing: Test the SCV 1 unlock solenoid coil for proper resistance and continuity. Inspect the wiring harness and connectors at the rear hydraulic block for connection problems.

1. 1

   Relieve hydraulic pressure

   Park the tractor on a level surface, lower all implements, turn off the engine, and cycle the hydraulic levers to relieve all residual hydraulic pressure in the system.

2. 2

   Locate SCV 1

   Locate External Hydraulic Valve 1 (SCV 1) at the rear hydraulic block.

3. 3

   Inspect electrical connector

   Disconnect the electrical harness connector from the SCV 1 solenoid. Clean the contacts and inspect for damaged pins or wiring faults.

4. 4

   Inspect and replace solenoid coil

   Remove the solenoid coil. If the coil failed the continuity test, replace it with a new OEM coil.

5. 5

   Extract SCV filter

   Carefully extract the small internal SCV filter (thimble filter) from the valve body.

6. 6

   Replace SCV filter

   If the filter is clogged with debris, replace it with a new one. Do not attempt to reuse a heavily soiled filter, as it will cause recurring electrical lockouts.

7. 7

   Replace SCV spool assembly

   If the valve spool itself is internally damaged or leaking, remove the entire SCV spool assembly and replace it.

8. 8

   Reassemble components

   Reassemble the solenoid and filter, and reconnect the wiring harness.

9. 9

   Test system

   Start the tractor, press the SCV unlock button in the cab, and verify that the red light stays solid (unlocked) rather than flashing. Test the remote with an implement to ensure proper hydraulic flow.