Massey Ferguson A.43.26 – EHR (Electronic Hitch/Hydraulic Control) system or main vehicle ECU: External Hydraulic Valve 4 Issue

This code indicates a malfunction, connection problem, or control error specifically isolated to the 4th external hydraulic spool valve (also known as a hydraulic remote).

• 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

   Verify Electrical Power: Low voltage can cause false EHR/hydraulic codes. Check the battery voltage under load and verify the alternator's charging output.

2. 2

   Inspect the Harness: Check the wiring harness leading to External Valve 4. Look for harness rub points, damaged pins in the solenoid connector, and verify ground integrity.

3. 3

   Test the Solenoid: Measure the coil resistance on the Valve 4 solenoid to ensure it is not open or shorted to ground.

4. 4

   Spool Leakage Check: If the electrical circuit is sound, perform a mechanical spool leakage check. Pressurize the port (up to 2500 psi if using a test kit) to see if oil leaks around the spool. Leakage indicates a damaged spool bore, a weak centering spring, or foreign matter inside the valve.

5. 5

   Fluid & Filter Inspection: Check hydraulic fluid levels, inspect the hydraulic filter for blockages, and look for sediment in the reservoir.

1. 1

   Stabilize the System

   Ensure the tractor is parked on level ground with the engine off and hydraulic pressure relieved before opening the system.

2. 2

   Resolve Wiring Faults

   If the diagnostic checks revealed harness rub points or a bad ground at the Valve 4 connector, repair the wiring or replace the damaged connector pigtail.

3. 3

   Replace the Solenoid (If Applicable)

   If the solenoid coil failed the resistance test, remove the retaining nut on the end of the spool valve and slide the old coil off. Install the new solenoid coil and torque to spec.

4. 4

   Clean and Unstick the Valve

   If the valve is mechanically stuck, remove the control valve assembly. Clean out any foreign matter. Sometimes manually moving the control valve lever back and forth can free a stuck detent.

5. 5

   Rebuild the Detent/Spool

   If the valve fails to hold position or the centering spring is weak, install a new spool detent kit. Use a thread locker (like Loctite) on the retaining screws during reassembly.

6. 6

   Replace the Valve Assembly

   If the spool bore is heavily scored or the valve body is cracked (which Massey Ferguson often only sells as a complete unit for certain series), remove the hydraulic lines, unbolt the valve block, and install a complete new external hydraulic spool valve.

7. 7

   Clear Codes and Test

   Reconnect all lines, top off the hydraulic fluid, and use a compatible diagnostic tool to clear the 0A.43.26 code. Test the remote valve under load to ensure proper operation.