Massey Ferguson A.2X.12 – Tractor Control Unit (TCU) or Autotronic 5 control unit: External Hydraulic Valve 2 Issue

The onboard diagnostic system has detected a malfunction in the second external hydraulic remote valve (spool valve 2). This is typically triggered by an electrical fault (such as an open circuit, short to ground, or short to power at the valve's solenoid), an implausible reading from the spool position sensor, or a mechanical issue where the main hydraulic valve is sticking and failing to return to the neutral position. The system automatically blocks/locks the affected valve to prevent unintended hydraulic movement.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Attempt to clear the error code from the control unit dashboard and restart the engine to see if the valve reactivates (rules out temporary voltage drop)

2. 2

   Inspect the wiring harness and electrical connector at External Hydraulic Valve 2 for corrosion, bent pins, or harness rub points

3. 3

   Test the resistance of the valve's solenoid coil using a multimeter and compare against OEM specs

4. 4

   Check live diagnostic data for the 'Spool Position Sensor Value' to verify if the voltage is out of range while the valve is stationary

5. 5

   Check hydraulic fluid level, ensure filters are clean, and inspect if the valve spool is physically sticking due to contamination

1. 1

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

   Relieve hydraulic pressure before beginning work.

2. 2

   Clean the rear remote valve stack thoroughly to prevent dirt from entering the hydraulic system during disassembly.

   Ensure the work area is clean to avoid contamination.

3. 3

   Locate External Hydraulic Valve 2. Disconnect the electrical harness from the valve's solenoid and the spool position sensor.

   Disconnect electrical connections to the affected valve.

4. 4

   If diagnostics pointed to a wiring issue, repair the damaged section of the harness or replace the connector pigtail.

   Address any identified wiring faults.

5. 5

   If the solenoid coil failed the resistance test, remove the retaining nut on the end of the spool, slide the old solenoid off, and install a replacement.

   Replace the solenoid if it failed electrical testing.

6. 6

   If the valve is mechanically sticking or leaking, the valve section must be removed. Unbolt the tie-rods holding the valve stack together and carefully extract Valve 2.

   Remove the valve section for mechanical issues.

7. 7

   Disassemble the spool valve on a clean workbench. Inspect the internal spool and bore for scoring or metal debris.

   Inspect the internal components for damage.

8. 8

   If the bore is in good condition, rebuild the valve using an OEM spool valve repair kit (replacing all O-rings, seals, and centering springs). If the bore is heavily scored, the entire valve section must be replaced.

   Rebuild or replace the valve section based on the condition of the bore.

9. 9

   Reassemble the valve stack, torquing the tie-rods to OEM specifications. Reconnect all hydraulic lines and electrical connectors.

   Reinstall the valve and reconnect all lines and harnesses.

10. 10

    Top up the hydraulic fluid, start the tractor, clear the codes from the dashboard, and test the remote valve operation for leaks and proper function.

    Restore fluid levels and verify the repair.