Massey Ferguson A.11.28 – Central vehicle control system: External Hydraulic Valve 1 Issue

Malfunction, electrical fault, or connection problem detected in the first external hydraulic remote valve (spool valve 1). Flagged when the valve fails to respond correctly to commands or when there is a break/short in the electrical circuit communicating with the valve.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5710
• 5711
• 5712
• 5713 SL
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S

1. 1

   Check the wiring harness leading to External Hydraulic Valve 1 for chafing, breaks, or corrosion.

2. 2

   Test the connector at the valve solenoid for proper voltage and ground.

3. 3

   Check the resistance of the valve's solenoid to ensure it is within OEM specifications (not shorted or open).

1. 1

   Secure the Machine

   Turn off the tractor, lower all hydraulic implements to the ground, and relieve all hydraulic system pressure.

2. 2

   Address Electrical Faults

   If the diagnostic checks reveal a wiring issue, repair or replace the damaged section of the wiring harness or the connector plugging into Valve 1.

3. 3

   Valve/Solenoid Replacement

   If the solenoid or valve itself has failed internally: Disconnect the electrical harness from External Hydraulic Valve 1. Unbolt the valve assembly from the hydraulic block. Clean the mating surface. Install the new valve or replacement solenoid, ensuring all O-rings and seals are properly seated and lubricated with clean hydraulic fluid. Torque the retaining bolts to the specification found in your model's service manual.

4. 4

   Clear Codes

   Reconnect the battery/harness, power on the tractor, and use a compatible Massey Ferguson diagnostic interface tool to clear the 0A.11.28 code from the system. Test the hydraulic remote for proper operation.