Massey Ferguson A.13.20 – Dash / Mid Mount Valve Module: External Hydraulic Valve 1 Issue
Issue description
Malfunction in the first external hydraulic remote valve (spool valve), typically triggered by a connection problem on the hydraulic valve, a loss of communication, or an out-of-range value from the valve's Spool Position Sensor.
Applies to these machines
40 machines- 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
- 7715
- 7715S
- 7716
- 7716S
- 7718
- 7718S
- 7719
- 7720
- 7720S
- 7722
- 7722S
- 7724
- 7724S
- 7726
- 7726S
Check the cause
Inspect the physical wiring harness and connectors at External Hydraulic Valve 1 for connection problems
Verify active communication between the Dash and the Mid Mount Valve Module
Monitor live data for the Spool Position Sensor on Valve 1 using a diagnostic tool, looking for erratic, frozen, or out-of-range voltage values
Check if the valve has lost its calibration parameters
Repair steps
Retrieve and Verify Codes
Connect a compatible diagnostic tool to the tractor to confirm that 0A.13.20 is the active code.
Inspect the Harness
Locate External Hydraulic Valve 1 at the rear remote stack (or mid-mount block). Disconnect the electrical connector to the valve's solenoid/sensor. Clean the contacts with electrical contact cleaner and inspect for broken wires or corrosion. Reconnect and test.
Test the Sensor
If the wiring is intact, the issue is likely internal to the Spool Position Sensor. If the sensor is removable on your specific valve block, test its resistance/voltage sweep.
Recalibrate the Valve
If the sensor is reading correctly but the code persists, initiate a hydraulic valve calibration procedure through the tractor's H-Menu or diagnostic tool.
Replace the Component
If the valve fails calibration or the spool position sensor is dead, replace the Spool Position Sensor (if serviced separately) or the External Hydraulic Valve 1 electronic control head.
Clear DTCs
After replacing the part, use the diagnostic tool to clear the 0A.13.20 code and cycle the hydraulic remote to ensure the fault does not return.
Parts you might need
(2)Spool Position Sensor
Exact OEM part numbers vary depending on whether the tractor is equipped with closed-center or open-center hydraulics, and often require looking up the specific valve block casting number.
External Hydraulic Valve 1 Assembly / Electronic Control Head
Replace if the sensor is not serviced separately.
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