Massey Ferguson A.33.1B – Tractor Control Unit (TCU) or Hydraulic/Implement Control Module: External Hydraulic Valve 3 Issue

Malfunction associated with the 3rd rear remote/external hydraulic valve. Typically an electrical fault (such as an open circuit, short circuit, or out-of-range voltage) at the solenoid that controls this specific spool valve, though it can also be triggered by low hydraulic pressure or a mechanical binding issue within the valve block itself.

• 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
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Visual Inspection: Locate the rear external hydraulic valve block. Inspect the wiring harness and the specific connector plugging into the Valve 3 solenoid for frayed wires, corrosion, or pushed-back pins.

2. 2

   Electrical Testing: Disconnect the solenoid for Valve 3. Use a multimeter to check the resistance (Ohms) across the solenoid coil pins. Compare the reading to a known good coil on Valve 1 or Valve 2. An open circuit or dead short indicates a burned-out coil.

3. 3

   Voltage Check: With the tractor key ON, actuate the Valve 3 control from the cab and verify that the ECU is sending the correct voltage signal to the connector.

4. 4

   Mechanical Check: Swap the solenoid coil from Valve 3 with Valve 2. If the fault code moves to Valve 2, the coil is the culprit. If the fault remains on Valve 3, the issue is either in the wiring harness leading to that specific plug or a mechanical jam inside the valve cartridge.

1. 1

   Preparation

   Park the tractor on a level surface, lower all implements, turn off the engine, and cycle the hydraulic levers/joystick to relieve all residual hydraulic pressure.

2. 2

   Access the Valve

   Locate the external hydraulic valve block at the rear of the tractor. Identify the solenoid corresponding to Valve 3.

3. 3

   Remove the Solenoid Coil

   Disconnect the electrical harness. Remove the retaining nut at the end of the solenoid stem. Slide the faulty solenoid coil off the valve cartridge.

4. 4

   Inspect the Cartridge

   Check the exposed valve stem for physical damage, leaking hydraulic fluid, or debris.

5. 5

   Install the New Part

   Slide the new solenoid coil onto the stem. Reinstall and tighten the retaining nut (do not overtighten, as this can crack the plastic coil housing).

6. 6

   Reconnect and Clear Codes

   Plug the electrical connector back in. Start the tractor and use a compatible Massey Ferguson diagnostic tool to clear the inactive 0A.33.1B code.

7. 7

   Test

   Actuate the 3rd remote valve to ensure proper operation and verify that the dashboard warning lights remain off.