Massey Ferguson 0A.73.28 – Implement/Hydraulic Control Module or Armrest control unit: External Hydraulic Valve 7 Issue

Malfunction, connection problem, or sensor reading error associated with the 7th external hydraulic remote/spool valve on the tractor's hydraulic 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

   Inspect Electrical Connections: Check the wiring harness and connector at External Hydraulic Valve 7.

2. 2

   Check Spool Position Sensor: Verify the spool position sensor value using a compatible diagnostic interface tool to see if the sensor is reading an open or short circuit.

3. 3

   Mechanical Neutral Check: Verify if the valve spool can physically be brought back to the neutral position.

1. 1

   Retrieve and Clear Codes

   Use a compatible diagnostic tool to read the active DTCs. Confirm 0A.73.28 is active.

2. 2

   Isolate the Valve

   Locate External Hydraulic Valve 7 on the rear remote valve stack.

3. 3

   Wiring Repair

   If the diagnostic check reveals a short or open circuit, repair or replace the damaged section of the wiring harness leading to the valve's solenoid/sensor.

4. 4

   Valve Replacement

   If the spool is mechanically seized or the internal position sensor has failed, relieve hydraulic system pressure, disconnect the hydraulic lines to Valve 7, and unbolt the valve section from the remote stack.

5. 5

   Install New Valve

   Bolt the replacement valve into the stack, reconnect the hydraulic lines to the specified torque, and plug in the electrical connector.

6. 6

   Calibration

   Use the diagnostic tool to clear the code and recalibrate the spool valve system so the ECU recognizes the new valve's position sensor sweep.