Massey Ferguson 0A.62.26 – Tractor Control Unit (TCU) or Auxiliary Valve Controller: External Hydraulic Valve 6 Issue

Malfunction in the circuit or mechanical operation of the 6th rear electro-hydraulic remote (EHR) spool valve. The underlying condition is typically an electrical failure (such as a short circuit, open circuit, or failed solenoid on the valve head) or a mechanical restriction (such as a stuck spool due to contaminated hydraulic fluid) preventing the valve from responding to the operator's command.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714S
• 7719S
• 8600 Series

1. 1

   Inspect the hydraulic fluid (UTTO) for low levels, burnt smell, or contamination (water/dirt). Check for a blocked hydraulic/transmission filter.

2. 2

   Inspect the wiring harness leading to the rear remote valve block for chafed wires or corroded pins at the connector for Valve 6.

3. 3

   Use a multimeter to check the resistance of the Valve 6 solenoid and compare it to a known working valve (e.g., Valve 5).

4. 4

   Swap the electrical connection or the solenoid head from Valve 6 to another valve slice to see if the fault code changes to the new valve number (indicating a faulty solenoid/electronic head) or remains 0A.62.26 (indicating a wiring harness or ECU issue).

5. 5

   Ensure the quick-release couplers on Valve 6 are not damaged or blocked, which can cause pressure deadheading.

1. 1

   Depressurize the System

   Lower all implements to the ground, turn off the tractor, and cycle the hydraulic controls to relieve all residual system pressure.

2. 2

   Clean the Area

   Thoroughly clean the rear hydraulic valve stack to prevent dirt from entering the hydraulic system during disassembly.

3. 3

   Address Electrical Faults

   If diagnostics pointed to a wiring issue, repair the broken wire or replace the damaged connector pigtail. If the solenoid failed, unbolt the electronic actuator head from the Valve 6 slice and install a replacement.

4. 4

   Address Mechanical Faults (Stuck Spool)

   If the valve is mechanically sticking, the specific valve slice must be removed from the stack. Unbolt the tie-rods holding the valve block together, carefully slide out the Valve 6 slice, disassemble the spool, clean it thoroughly with solvent, and inspect for scoring. Replace all internal O-rings and seals using an OEM seal kit.

5. 5

   Reassembly

   Reinstall the valve slice, torque the stack tie-rods to factory specifications, and reconnect the wiring harness.

6. 6

   Fluid Maintenance

   If the fluid was contaminated, drain the hydraulic system, replace the hydraulic/transmission filters, and refill with fresh OEM-spec UTTO fluid.

7. 7

   Clear Codes

   Use a compatible diagnostic tool to clear the 0A.62.26 fault code and test the remote valve under load.