Massey Ferguson A.71.12 – Hydraulic Control Unit / Armrest Controller: External Hydraulic Valve 7 Issue

Indicates an electrical or connection problem within the circuit of the 7th external hydraulic remote valve. Triggered when the system detects an implausible condition, such as an open circuit, a short to ground, a short to power, or a missing signal at the valve's solenoid.

• 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

   Locate the rear remote valve stack and identify Valve 7. Inspect the wiring harness leading to the solenoid for rub points, melted insulation, or severed wires.

2. 2

   Disconnect the solenoid connector. Check for moisture ingress, corrosion, or bent pins, which are common causes for connection problem faults.

3. 3

   Use a multimeter to measure the resistance across the solenoid coil pins. An infinite reading indicates an open circuit (blown coil), while a reading of zero indicates a short.

4. 4

   Verify ground integrity at the harness and check that the controller is sending the proper voltage signal to the connector when the remote is actuated from the cab.

1. 1

   Depressurize

   Turn off the tractor, lower all implements, and cycle the hydraulic levers to relieve all hydraulic pressure in the system.

2. 2

   Disconnect

   Unplug the electrical harness from the External Hydraulic Valve 7 solenoid.

3. 3

   Wiring Repair

   If the diagnostic checks revealed a broken wire or corroded connector, splice in a new pigtail connector or repair the harness using weather-sealed heat shrink.

4. 4

   Solenoid Replacement

   If the solenoid coil failed the resistance test, remove the retaining nut at the end of the valve cartridge and slide the old coil off. Slide the new OEM coil on, tighten the nut, and plug in the connector.

5. 5

   Valve Section Replacement

   If the electrical components are sound but the valve is internally shorted or mechanically seized, the specific proportional valve section must be unbolted from the hydraulic stack and replaced.

6. 6

   Clear Codes

   Use a compatible Massey Ferguson diagnostic tool to clear the 0A.71.12 code and test the remote valve for proper operation.