Massey Ferguson A.42.20 – Armrest Controller or Electronic Hitch/Hydraulic Control Module (EHR): External Hydraulic Valve 4 Issue

Malfunction in the 4th external hydraulic remote (spool valve), typically triggered when the control unit detects an open circuit, a short to ground, a signal voltage issue, or an implausible spool position sensor value.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 5600 Series
• 5608
• 5609
• 5610
• 5613
• 6400 Series
• 6480
• 6600 Series
• 6615
• 7400 Series
• 7600 Series
• 7614
• 7626
• 7700 Series Tier 4
• 7714
• 7718S
• 7726S
• 8600 Series

1. 1

   Inspect the electrical connector at the #4 external hydraulic valve for dirt, corrosion, or loose pins, and check the wiring harness for rub points, open circuits, or shorts to ground

2. 2

   Measure the resistance of the solenoid coil on the #4 valve to ensure it is not burnt out or shorted

3. 3

   Use a diagnostic tool to read the live spool position sensor value to check for erratic or out-of-tolerance readings

4. 4

   Check the hydraulic fluid level and filter condition, as aeration or contamination can cause the valve spool to stick or vibrate

1. 1

   Depressurize the System

   Turn off the tractor and relieve all hydraulic pressure by cycling the hydraulic levers/controls before beginning work.

2. 2

   Inspect/Repair Wiring

   Disconnect the 4-pin electrical harness from the #4 spool valve. Clean the connector with contact cleaner. If the harness is damaged, repair the wiring and clear the code to see if it returns.

3. 3

   Replace the Electronic Slice/Solenoid

   If the wiring is intact but the solenoid or position sensor is dead, remove the electronic spool slice head from the valve block.

4. 4

   Inspect the Valve Block

   If the electronic head is functioning but the valve is mechanically binding, remove the entire valve block. Clean the assembly and replace the internal O-rings/seals. If the internal bore is scored, the entire spool valve assembly must be replaced.

5. 5

   Reassembly and Bleeding

   Install the new spool valve or electronic head. Torque hydraulic unions to OEM specifications. Top off the hydraulic fluid and bleed the system to remove any trapped air.

6. 6

   Calibration

   Connect a diagnostic tool to clear the fault codes. Note that installing a new electric spool slice often requires the new component to be programmed/calibrated to the tractor's ECU.