Massey Ferguson A.62.28 – Onboard Diagnostic System / Hydraulic Control Module: External Hydraulic Valve 6 Issue

Malfunction in the circuit or mechanical operation of the 6th rear remote hydraulic spool valve. The system has detected that the valve is either not responding to electrical commands, is experiencing a voltage/current irregularity (such as an open circuit or short), or is failing to achieve the commanded hydraulic pressure/flow.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4700 Series
• 4707
• 4708
• 4709
• 4710
• 5600 Series
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5700SL Series
• 7600 Series
• 7614-7626
• 7700 Series
• 7714-7726S
• 8600 Series

1. 1

   Check the hydraulic fluid (UTTO) level and condition, as contaminated oil or a blocked hydraulic/transmission filter can restrict flow.

2. 2

   Inspect External Valve 6 for physical damage, leaking seals, or damaged quick-couplers.

3. 3

   Check the wiring harness and the electrical connector at Valve 6 for corrosion, loose pins, or chafed wires causing a short or open circuit.

4. 4

   Swap the electrical connector from Valve 6 to another known-good valve (like Valve 5) to isolate the issue. If the fault moves, the issue is in the wiring or ECU; if it remains, the spool valve is faulty.

1. 1

   Depressurize the System

   Turn off the tractor and cycle the hydraulic levers/joysticks to relieve all residual hydraulic pressure in the system.

2. 2

   Clean the Area

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

3. 3

   Disconnect

   Unplug the electrical harness connector from External Valve 6.

4. 4

   Remove Lines

   Disconnect the hydraulic hoses and lines attached to the valve. Cap the lines immediately to prevent fluid loss and contamination.

5. 5

   Unbolt the Valve

   Remove the mounting bolts securing Valve 6 to the hydraulic valve block/stack.

6. 6

   Repair or Replace

   Depending on the damage, either install a completely new spool valve assembly or rebuild the existing valve on a clean workbench using an OEM seal/repair kit (replacing O-rings, backup washers, and seals).

7. 7

   Reinstallation

   Mount the new/rebuilt valve to the stack, torque the bolts to the manufacturer's specification, and reconnect the hydraulic lines and electrical harness.

8. 8

   Bleed and Test

   Top up the hydraulic fluid (e.g., 10W40 UTTO). Start the tractor, allow the fluid to warm up, and cycle Valve 6 multiple times to bleed air from the system. Check for leaks.

9. 9

   Clear Codes

   Use a compatible diagnostic tool to clear the 0A.62.28 DTC from the system.