Fendt A.1.12 – A002 - ECU, enhanced control: Y015 - Auxiliary control valve (Spool Valve 1) supply voltage below 8V

The system has detected that the supply voltage to the Y015 auxiliary control valve (Spool Valve 1) has dropped below 8 volts. As a safety measure, the affected valve automatically moves into the neutral position, and valve operation becomes unavailable.

• 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
• 400 Vario series
• 411
• 412
• 413
• 414
• 415
• 700 Vario series
• 712
• 714
• 716
• 718
• 800 Vario series
• 818
• 820
• 900 Vario series
• 916
• 920
• 924
• 926
• 930

1. 1

   Locate the Y015 auxiliary control valve (Control valve, position 1, color-coded yellow) on the rear hydraulic block.

2. 2

   Disconnect the harness at the Y015 valve and measure the supply voltage to check for a voltage drop below 8V, poor ground, or a short circuit.

3. 3

   Check the power supply for the CAN bus located on the main printed circuit board (A013), specifically inspecting fuses F040 and F041.

4. 4

   Check the signal flow and wiring harness back to the A002 ECU, specifically testing CAN II pins 4 and 5 for continuity and data transfer integrity.

1. 1

   Preparation

   Park the tractor on a level surface, apply the handbrake, and turn the ignition ON to access the Vario terminal.

2. 2

   Inspect Connections

   Clean the electrical connector at the Y015 (yellow) valve. Agricultural environments often cause corrosion that leads to high resistance and voltage drops.

3. 3

   Repair Wiring/Fuses

   If fuses F040/F041 are blown, replace them. If the voltage at the valve connector is still below 8V, trace the wiring harness back to the A002 ECU and repair any broken or chafed wires.

4. 4

   Replace the Valve/Solenoid

   If the ECU is outputting the correct voltage and the wiring is intact, the solenoid coil on the Y015 valve has likely failed internally and is pulling the voltage down. Replace the solenoid or the spool valve section.

5. 5

   Clear Fault Codes

   Once the repair is made, use the Vario terminal or FENDIAS diagnostic software to clear the stored A.1.12 fault code from the A002 ECU memory.

6. 6

   Test Operation

   Operate Valve 1 via the joystick or terminal to ensure it no longer defaults to the neutral position and full hydraulic flow is restored.