Massey Ferguson 0A.21.1B – Mid Mount Valve Module: External Hydraulic Valve 2 Issue

Indicates a fault within the hydraulic control system, typically caused by a connection problem on a hydraulic valve or an issue with the spool position sensor value.

• 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

   Retrieve and verify all active DTCs using a diagnostic tool to confirm if 0A.21.1B is accompanied by spool position sensor errors (M17-M19) or dash communication errors (M16).

2. 2

   Visually inspect the wiring harness, connectors, and pins leading to External Hydraulic Valve 2 and the Mid Mount Valve Module for corrosion, damage, or loose fittings.

3. 3

   Test the spool position sensor values using a diagnostic tool to determine if the sensor is reading out of range or failing to register movement.

1. 1

   Resolve Wiring Faults

   If the diagnostic checks reveal a damaged connector or broken wire at External Hydraulic Valve 2, repair or replace the affected harness section.

2. 2

   Replace the Spool Position Sensor / Valve

   If the wiring is intact but the spool position sensor value remains erratic or missing, the sensor or the electric spool valve control switch must be replaced.

3. 3

   Reassemble and Re-test

   Once the new valve, sensor, or repair kit is installed, reconnect the hydraulic lines (ensuring no sealant is used on o-ring or flare adapter threads).

4. 4

   Clear Codes

   Use the diagnostic interface tool to clear the 0A.21.1B fault code from the system and cycle the hydraulic remote to ensure the code does not return.