Massey Ferguson A.43.1A – Onboard diagnostic system: External Hydraulic Valve 4 Issue

Malfunction in the circuit for the 4th external hydraulic remote (spool valve), typically caused by an electrical connection problem to the hydraulic valve solenoid, a sticking spool valve, or a failure in the valve's internal seals causing a loss of pressure or function.

• 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
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S

1. 1

   Inspect electrical connections at External Hydraulic Valve 4 for corrosion, loose pins, or broken wires (electrical cause)

2. 2

   Check for sticking by testing the hydraulic remote manually or via cab controls (mechanical cause)

3. 3

   Inspect the spool valve body for external fluid leaks, indicating failed internal seals (seal failure cause)

4. 4

   Verify pump pressure to ensure the hydraulic pump is building adequate pressure and the issue is isolated to Valve 4

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent electrical shorts while working on the valve solenoids.

2. 2

   Relieve Hydraulic Pressure

   Relieve all hydraulic pressure from the system before unbolting any lines or couplers.

3. 3

   Address Wiring

   If the diagnostic check revealed a damaged connector at Valve 4, splice in a new pigtail connector or clean the contacts with electrical contact cleaner.

4. 4

   Remove the Spool Valve

   If the valve is leaking or sticking, disconnect the hydraulic lines and unbolt External Hydraulic Valve 4 from the valve stack.

5. 5

   Rebuild or Replace

   To rebuild: Disassemble the spool valve and install a spool valve repair kit (replacing all O-rings and seals). To replace: Install a completely new external hydraulic valve assembly.

6. 6

   Reinstall and Test

   Bolt the valve back into the stack, reconnect the hydraulic lines, and plug in the electrical connector.

7. 7

   Clear the Code

   Use a compatible Massey Ferguson diagnostic tool or interface device to clear the A.43.1A DTC from the system. Test the hydraulic remote under load to ensure the code does not return.