Massey Ferguson 0A.33.28 – Tractor Control Unit (TCU) or Implement/Hydraulic Control Module: External Hydraulic Valve 3 Issue

This code indicates a connection problem, electrical fault, or mechanical failure specifically isolated to the third external hydraulic remote valve (spool valve 3).

• 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

   Inspect the electrical connector on Valve 3 for dirt ingress, loose screw collars, and ensure pins are clean and making solid contact.

2. 2

   Test the solenoid on top of the Valve 3 rock shaft/spool block for proper voltage and function (manually push in from the rear to check mechanical actuation).

3. 3

   Check hydraulic fluid (UTTO specification) for correct level and cleanliness, as contaminated fluid or clogged filters can cause valves to stick.

4. 4

   Ensure the system isn't stuck in a safety lockout by cycling the switches to clear any lockouts.

1. 1

   Depressurize the System

   Turn off the tractor and cycle the hydraulic levers/switches to relieve any residual pressure in the system before working on the valves.

2. 2

   Clean and Re-seat Connections

   Disconnect the wiring harness at External Valve 3. Clean the contacts with electrical contact cleaner, ensure the screw collar is tight, and re-seat the plug. Clear the code and test.

3. 3

   Replace the Solenoid

   If the wiring is intact but the valve fails to actuate electronically, remove the retaining nut on the Valve 3 solenoid and slide the coil off the valve stem. Install a new solenoid coil, plug it in, and test.

4. 4

   Replace the Valve Assembly

   If the solenoid is functioning but the valve is mechanically seized or leaking internally, the spool valve section will need to be replaced. Unbolt the Valve 3 section from the hydraulic remote stack, ensuring you replace the O-rings between the valve slices when installing the new unit.

5. 5

   Clear Codes

   Use a compatible Massey Ferguson diagnostic tool to clear the 0A.33.28 code from the system memory.