Massey Ferguson 0A.43.28 – Basic Control Unit ECU (A050) or Multifunction Armrest (MFA): External Hydraulic Valve 4 Issue

Malfunction associated with the 4th external hydraulic remote (spool valve). The fault is typically triggered by an electrical connection problem, a CAN bus communication error, a potentiometer/solenoid failure on the valve itself, or a plausibility error where the valve is not responding correctly to operator inputs.

• 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 harness leading to the 4th external hydraulic valve at the rear of the tractor for chafing, breaks, or melted wires.

2. 2

   Disconnect the 4-pin connector at the spool valve and inspect for corrosion, moisture, or bent pins.

3. 3

   Use a multimeter to check the resistance of the valve's solenoid and verify that it is receiving the correct voltage from the ECU when the remote is activated.

4. 4

   Verify CAN bus integrity by ensuring there are no other CAN bus communication codes present, which could indicate a broader network issue rather than a localized valve failure.

1. 1

   Power down the tractor and disconnect the battery to prevent electrical shorts.

   Power down the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the external hydraulic valve block assembly at the rear of the machine. Identify the 4th spool valve section.

   Locate the external hydraulic valve block assembly at the rear of the machine. Identify the 4th spool valve section.

3. 3

   Disconnect the 4-pin electrical connector from the faulty valve. Clean the contacts with electrical contact cleaner. If the connector was heavily corroded, replace the pigtail connector.

   Disconnect the 4-pin electrical connector from the faulty valve. Clean the contacts with electrical contact cleaner. If the connector was heavily corroded, replace the pigtail connector.

4. 4

   If the wiring is sound but the valve failed electrical testing, the electronic spool valve section must be replaced. Unbolt the faulty spool valve from the hydraulic block (be prepared to catch residual hydraulic fluid).

   If the wiring is sound but the valve failed electrical testing, the electronic spool valve section must be replaced. Unbolt the faulty spool valve from the hydraulic block (be prepared to catch residual hydraulic fluid).

5. 5

   Install the new hydraulic electric spool valve, ensuring all O-rings and seals are properly seated.

   Install the new hydraulic electric spool valve, ensuring all O-rings and seals are properly seated.

6. 6

   Torque the mounting bolts to the manufacturer's specification and reconnect the 4-pin electrical connector.

   Torque the mounting bolts to the manufacturer's specification and reconnect the 4-pin electrical connector.

7. 7

   Reconnect the battery, top off the hydraulic fluid if necessary, and use a compatible diagnostic tool to clear the 0A.43.28 fault code.

   Reconnect the battery, top off the hydraulic fluid if necessary, and use a compatible diagnostic tool to clear the 0A.43.28 fault code.

8. 8

   Test the 4th hydraulic remote for proper operation.

   Test the 4th hydraulic remote for proper operation.