Massey Ferguson 0A.42.27 – Armrest Controller / DCC3 or Hydraulic Control Module: External Hydraulic Valve 4 Issue / Switch On Mud Guard For Hydraulics Spool Valve Signal Voltage Issue (HITCH)

An electrical fault (such as a signal voltage out of range, an open circuit, or a short to ground) affecting the 4th external hydraulic spool valve or the external mudguard switch that controls it. The tractor's onboard diagnostic system detects that it cannot properly communicate with or control the Valve 4 solenoid.

• 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

1. 1

   Inspect Wiring and Connectors: Check the Valve 4 solenoid connector and the mudguard switch harness for rub points, frayed wires, or corrosion.

2. 2

   Test the Mudguard Switch: Since the code specifically mentions a signal voltage issue from the mudguard switch, test the switch for proper voltage output and continuity.

3. 3

   Check Coil Resistance & Ground: Measure the coil resistance on the Valve 4 solenoid and verify ground integrity to rule out a dead solenoid.

4. 4

   Inspect Spool Valve Cables: Check the spool valve control cables for physical damage or binding.

5. 5

   Check Hydraulic Fluid & Filters: Ensure the UTTO (Universal Tractor Transmission Oil) fluid is at the correct level and the hydraulic/transmission filters are not blocked, as contaminated fluid can cause valves to stick and throw secondary codes.

1. 1

   Preparation

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

2. 2

   Access the Valve Block

   Locate the external hydraulic valve block at the rear of the tractor and identify the slice for Valve 4.

3. 3

   Wiring Repair

   If the diagnostic checks revealed a damaged harness or connector at the mudguard switch or the valve solenoid, repair the wiring or replace the connector.

4. 4

   Switch Replacement

   If the mudguard switch failed the continuity/voltage test, disconnect it from the harness, unbolt it from the mudguard housing, and install a new switch.

5. 5

   Valve Slice Replacement

   If Solenoid/Valve is faulty: Disconnect the electrical harness from the Valve 4 electric spool slice. Remove the retaining bolts holding the valve slice to the manifold block. Carefully remove the faulty electric spool slice, ensuring no dirt or debris enters the hydraulic system. Install the new electric spool slice using new O-rings/seals to prevent leaks. Torque the retaining bolts to the manufacturer's specification and reconnect the electrical harness.

6. 6

   Programming

   Note that a new electric spool slice must be programmed to the tractor's ECU using a compatible Massey Ferguson diagnostic tool.

7. 7

   Testing

   Top up the hydraulic fluid if any was lost. Start the tractor, test the operation of Valve 4 via the cab controls and the mudguard switch, and clear the DTC from the system.