Massey Ferguson A.41.18 – Onboard diagnostic system / main vehicle ECU (Tractor Control Unit or Autotronic module): External Hydraulic Valve 4 Issue

This code indicates a connection problem, electrical fault, or operational failure on the 4th external hydraulic remote valve (spool valve). The system has detected an open circuit, short circuit, or lack of response from the electronic solenoid controlling this specific valve slice.

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

1. 1

   Locate the rear external hydraulic valve block and identify Valve 4 (usually the 4th slice in the stack).

2. 2

   Disconnect the electrical connector to the Valve 4 solenoid. Inspect the wiring harness for chafing, breaks, or corrosion. Check the connector pins for pushed-out terminals or moisture ingress.

3. 3

   Use a multimeter to test the resistance of the solenoid coil on Valve 4. Compare the reading to a known good valve (e.g., Valve 1, 2, or 3).

4. 4

   Perform a swap test: Swap the electrical connector from Valve 4 with the connector for Valve 3. Turn the key on and check the active fault codes. If the code changes to the equivalent code for Valve 3, the issue is the valve solenoid itself. If the code remains A.41.18, the issue is in the wiring harness or the ECU.

5. 5

   Ensure hydraulic fluid levels are correct and that there is no physical binding or mechanical blockage in the spool itself.

1. 1

   Depressurize the System

   Park the tractor on a level surface, lower all implements to the ground, and turn off the engine. Cycle the remote levers/buttons inside the cab to relieve any residual hydraulic pressure.

2. 2

   Clean the Area

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

3. 3

   Address Electrical Faults (If Applicable)

   If the diagnostic checks revealed a corroded connector, clean the pins with electrical contact cleaner, apply dielectric grease, and reconnect. If the wiring harness is damaged, splice and repair the broken wires using weather-sealed connectors.

4. 4

   Replace the Solenoid/Valve

   If the solenoid coil is dead, remove the retaining nut at the end of the valve cartridge and slide the old coil off. Slide the new coil on and tighten the nut. If the entire valve slice needs replacement, place a catch pan underneath the valve stack. Unbolt the tie rods holding the valve stack together. Carefully separate the stack and remove the faulty Valve 4 slice. Install the new valve section, ensuring all O-rings between the slices are seated correctly.

5. 5

   Reassembly

   Re-torque the valve stack tie rods to OEM specifications. Reconnect the electrical harness.

6. 6

   Bleed and Clear

   Top up the hydraulic fluid. Start the tractor, operate the valve to bleed any trapped air, and use a compatible diagnostic tool to clear the 0A.41.18 DTC from the system.