Massey Ferguson 0A.42.20 – Auxiliary Valve Controller: External Hydraulic Valve 4 Issue

Fault within the auxiliary hydraulic system, specifically the 4th external spool valve. Indicates a specific electrical or mechanical fault state, which typically points to a connection problem, a spool position sensor value out of range, or a solenoid failure.

• 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

1. 1

   Visual Inspection: Check the electrical harness connected to the #4 external hydraulic spool valve. Look for corrosion, bent pins, or water ingress in the connector.

2. 2

   Wiring Continuity: Inspect the wiring harness between the valve and the Auxiliary Valve Controller for chafing, breaks, or shorts to ground.

3. 3

   Coil Resistance Test: Test the solenoid coil resistance with a multimeter to ensure it is within OEM specifications (not open or shorted).

4. 4

   Sensor Verification: Check the spool position sensor for correct voltage feedback.

5. 5

   Hydraulic System Check: Verify the hydraulic oil level and ensure the transmission/hydraulic oil filters are not blocked.

6. 6

   Software Calibration: Attempt to clear the code and recalibrate the spool valves via the tractor's Datatronic/Fieldstar terminal or an AGCO dealer diagnostic tool.

1. 1

   Relieve hydraulic pressure

   Park the tractor on a level surface, lower all implements, turn off the engine, and relieve all hydraulic pressure by moving the control levers/joystick.

2. 2

   Locate Valve #4

   Locate the rear external hydraulic valve block. Identify Valve #4 (usually counted from left to right or top to bottom depending on the stack configuration).

3. 3

   Disconnect electrical harness

   Disconnect the electrical harness from the Valve 4 solenoid and position sensor.

4. 4

   Replace solenoid coil (if applicable)

   If replacing the solenoid coil only: Remove the retaining nut at the end of the valve stem, slide the old coil off, install the new coil, and tighten the nut.

5. 5

   Clean valve block area

   If replacing the entire valve slice: Thoroughly clean the area around the valve block to prevent dirt from entering the hydraulic system.

6. 6

   Remove tie rods

   Remove the tie rods or mounting bolts holding the valve stack together.

7. 7

   Remove faulty valve slice

   Carefully remove the faulty Valve 4 slice. Note: Be extremely careful not to lose or pinch the O-rings located between the slices.

8. 8

   Install new valve slice

   Install the new valve slice using brand new O-rings.

9. 9

   Reassemble valve stack

   Reassemble the valve stack and torque the tie rods to the manufacturer's specification.

10. 10

    Reconnect electrical harnesses

    Reconnect the electrical harnesses.

11. 11

    Test and calibrate

    Start the tractor, check for hydraulic leaks, and use the in-cab terminal or dealer diagnostic tool to calibrate the new valve.