Massey Ferguson 0A.40.1B – Onboard diagnostic system: External Hydraulic Valve 4 Issue

The tractor's onboard diagnostic system has detected a malfunction, electrical fault, or operational issue specifically within the 4th external hydraulic remote/spool valve circuit.

• 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

   Use a compatible diagnostic tool to confirm 0A.40.1B is active

2. 2

   Check the wiring harness and electrical connectors leading to External Hydraulic Valve 4 for loose or corroded connections

3. 3

   Inspect the valve slice for physical damage, sticking spools, or hydraulic fluid leaks

4. 4

   Test the pilot pressure control and solenoids on the valve for proper voltage and resistance to determine if the electrical slice has failed

1. 1

   Depressurize and Power Down

   Ensure the tractor is turned off, the battery is disconnected, and all hydraulic system pressure is relieved before servicing.

2. 2

   Wiring Repair

   If the diagnostic check revealed a loose or corroded connection at Valve 4, clean the contacts, repair the wiring harness, and reconnect.

3. 3

   Valve Replacement

   If the electric spool valve has failed internally: Disconnect the hydraulic lines from the 4th valve slice. Unbolt and remove the faulty electric spool slice. Install the replacement electric spool slice (or rebuild the mechanical components using an OEM repair kit if applicable). Reconnect all hydraulic lines and electrical connections.

4. 4

   Programming

   If a new electric spool slice is installed, it must be programmed/calibrated to the tractor's ECU using a dealer diagnostic tool.

5. 5

   Clear Codes

   Clear the 0A.40.1B DTC from the system and test the hydraulic remote for proper operation.