Fendt A.1.6C – A050 - ECU, basic control unit: Actuator not in neutral during RUNUP

The system detects that the steering actuator spool cannot reach or return to its neutral position when the tractor and steering system initialize. This is typically caused by a mechanical fault on the steering actuator itself or a failure of the internal position sensor.

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 200 Vario (V / F / P)
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III, S4)
• Fendt 900 Vario (COM III, S4, Gen6)

1. 1

   Check for mechanical binding: Ensure the front wheels have complete freedom of movement and are not mechanically bound or obstructed.

2. 2

   Inspect wiring and sensor: Check the wiring harness connecting to the position sensor on the Y087 steering valve block for broken wires, chafing, or short circuits.

3. 3

   Verify supply voltage: Check the voltage to the steering valve block to ensure it is stable (between 10V and 32V).

4. 4

   Perform actuator test: Use the FENDIAS / SERDIA service diagnostics program to read the measured values of the steering angle sensor and test the steering valve actuation.

1. 1

   Access the Valve Block

   The Y087 steering valve block is located on the right side of the transmission. To access it safely, you must remove the right rear wheel and the side panel.

2. 2

   Relieve Pressure

   Ensure the engine is switched off and relieve all hydraulic pressure from the steering and suspension systems before disconnecting any lines.

3. 3

   Inspect/Replace the Steering Head

   If the wiring is intact but the actuator cannot find neutral, the mechanical fault is internal. You must check the steering valve and replace the steering head/actuator unit.

4. 4

   Replace the Valve Block (if necessary)

   If the position sensor or spool is irreparably damaged, replace the entire Y087 Auto-Guide steering valve block.

5. 5

   System Calibration

   After replacing the steering head or the entire valve block, the new steering valve must be calibrated. Enter Calibration code "2403" in the tractor's terminal to initiate the steering valve calibration. Ensure the wheels are perfectly straight before starting the calibration.