Massey Ferguson A.22.28 – Onboard Diagnostic System / Hydraulic Control Module: External Hydraulic Valve 2 Issue

Malfunction in the electronic control, position feedback, or hydraulic flow of the tractor's second rear remote spool valve. It typically means the tractor's computer is not receiving the correct position signal from the valve's sensor, or the valve is physically sticking and failing to respond to electronic commands.

• 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 to 7726S

1. 1

   Verify the hydraulic fluid level and inspect the hydraulic/transmission filter for contamination or blockages (restricted flow cause).

2. 2

   Inspect the wiring harness and electrical connector at External Valve 2 for corrosion or water ingress (electrical/sensor cause).

3. 3

   Check for mechanical jamming caused by debris or internal wear that may cause the hydraulic spool valve to stick (mechanical cause).

4. 4

   Test the spool position sensor if the implement is 'hunting' (moving up and down) or the valve is completely dead (sensor failure cause).

1. 1

   Relieve Pressure

   Ensure the tractor is off, implements are lowered, and all hydraulic pressure is relieved from the system.

2. 2

   Clean the Area

   Thoroughly clean the area around the hydraulic lift cover and External Valve 2 to prevent dirt from entering the hydraulic system.

3. 3

   Disconnect Electronics

   Unplug the electrical connector from the spool valve position sensor. Clean the harness side of the connection and ensure it is dry.

4. 4

   Remove the Sensor/Valve

   Unbolt the faulty position sensor from its direct mounting on the hydraulic valve block/lift cover. If the valve itself is jammed, the spool valve assembly will need to be removed and rebuilt/replaced.

5. 5

   Install the New Part

   Install the replacement sensor or valve. Ensure all O-rings and seals are properly seated, as moisture is the primary enemy of these electronic components.

6. 6

   Recalibrate the System

   After installation, the tractor will require a recalibration procedure so the ECU can learn the new sensor's parameters. This usually requires a dealer diagnostic tool or following the specific setup procedure in the service manual.