Fendt 0A.1.XC – Basic Control Unit (ECU A050): Auxiliary Hydraulic Control Valve Fault

Indicates a fault with an auxiliary hydraulic control valve, where the system detects 'Manual actuation' (valve physically deflected or jammed away from its neutral position) or the valve is failing to report to the CAN bus. As a safety measure, all valve positions lose function, the affected valve is locked, and the pilot pressure is turned OFF.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 200 Vario series
• 300 Vario series
• 400 Vario series
• 500 Vario series
• 700 Vario series
• 800 Vario series
• 900 Vario series

1. 1

   Identify the Specific Valve: Use the tractor's multiple display terminal or a diagnostic tool (such as TEXA Navigator or FENDIAS) to read the exact code to determine which valve (Y071 through Y080) is malfunctioning.

2. 2

   Visual & Mechanical Inspection: Check the affected spool valve to see if it is physically jammed, bound, or manually deflected from its neutral resting position.

3. 3

   Electrical & CAN Bus Check: Inspect the wiring harness and connectors at the valve to see if it lost communication with the Hydraulic Valve Bus.

4. 4

   Hydraulic Pressure Test: Verify that the pilot pressure is actually off and ensure there are no blockages in the hydraulic lines leading to the valve block.

1. 1

   Relieve Pressure

   Turn off the tractor and safely relieve all hydraulic system pressure before servicing the valve block.

2. 2

   Access the Valve Block

   Locate the auxiliary control valve block (usually at the rear for valves Y074-Y080, or middle for Y071/Y072).

3. 3

   Disconnect Electronics

   Unplug the CAN bus electrical connector from the specific faulty valve identified by the code.

4. 4

   Remove the Valve

   Unbolt and carefully remove the faulty spool valve/solenoid from the hydraulic manifold.

5. 5

   Install Replacement

   Clean the mounting surface and install the new OEM control valve. Ensure O-rings/seals are properly seated.

6. 6

   Reconnect and Reassemble

   Reconnect the electrical harness to the new valve.

7. 7

   Clear Fault Codes

   Turn the tractor on. Note that Fendt systems require each stored fault code to be cleared individually through the terminal; otherwise, the message will display again on startup.

8. 8

   Test Operation

   Actuate the hydraulic controls to ensure the new valve returns to neutral automatically and communicates properly with the CAN bus without throwing a code.