Massey Ferguson 0A.23.18 – Tractor Control Unit (TCU) or Hydraulic/Transmission ECU: External Hydraulic Valve 2 Issue

Malfunction associated with the second external hydraulic remote valve. Typically an electrical connection problem on the hydraulic valve or an issue with the spool position sensor value.

• 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

   Scan for sub-codes (such as M20 or M21) using a compatible diagnostic tool to check for specific spool position sensor value issues.

2. 2

   Visually inspect the wiring harness routing to External Hydraulic Valve 2 at the rear remote block for chafing, cuts, or heat damage.

3. 3

   Disconnect the electrical connector at the valve and check for moisture, dirt, corrosion, or pushed-back pins (most common cause of connection faults).

4. 4

   Test the solenoid and the spool position sensor for proper resistance and continuity according to OEM service manual specifications.

1. 1

   Preparation

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

2. 2

   Clean the Area

   Thoroughly clean the rear remote valve block area to prevent dirt from entering the hydraulic system during repair.

3. 3

   Address Wiring/Connections

   If the diagnostic check revealed a corroded or loose connector, clean the pins with contact cleaner, apply dielectric grease, and reconnect securely.

4. 4

   Component Replacement

   If the solenoid or spool position sensor failed the electrical test, remove the retaining bolts securing the electronic control head/solenoid to the mechanical spool valve.

5. 5

   Install New Parts

   Install the replacement pilot pressure control, solenoid, or complete spool valve assembly. Ensure all O-rings are seated correctly and torque the mounting bolts to OEM specifications.

6. 6

   Reassembly and Testing

   Reconnect the electrical harness. Turn on the tractor, use the diagnostic tool to clear the 0A.23.18 fault code, and cycle External Valve 2 multiple times to ensure the code does not return and the hydraulic remote functions properly.