Fendt 9.1.55 – ECU, enhanced control, electric auxiliary control valves (A002): Spool valve fault — Overvoltage (> 45 volts)

The system has detected an excessively high voltage (greater than 45 volts) at the Y019 spool valve. As a safety consequence, the system forces the valve to move into the neutral position, disabling its function.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• Fendt Farmer 400 Vario
• Fendt Favorit 700 Vario
• Fendt Favorit 900 Vario
• Fendt 300, 400, 700, 800, and 900 Vario series (including COM III models)

1. 1

   Check fuses F040 and F041 on printed circuit board A013, which supply voltage for the CAN bus and auxiliary valves.

2. 2

   Inspect connectors X640 (+UB), X641 (CAN high), and X642 (CAN low) for the Y015-Y019 valve block.

3. 3

   Test the wiring harness leading to the Y019 valve for a short to a high-voltage source.

4. 4

   Disconnect the Y019 valve and measure the voltage at the harness side to isolate if the fault is internal to the valve's electronics.

1. 1

   Locate the Valve

   The Y019 valve (also designated as "Valve 5" or the auxiliary control valve for the front power lift) is located on the right side of the tractor, near the right entry step, directly behind the hydraulic oil tank.

2. 2

   Access the Component

   Remove the metal footplate/panel or access flap to expose the central control block (ZSB).

3. 3

   Inspect and Repair Wiring

   If the diagnostic checks revealed damaged wiring or a short circuit at connectors X640, X641, or X642, repair the harness as necessary.

4. 4

   Replace the Valve

   If the wiring is intact and the fault is internal to the valve's electronic control head: Relieve all hydraulic pressure from the system. Disconnect the electrical connectors from the Y019 valve slice. Unbolt the Y019 valve section from the Bosch Rexroth SB23 valve stack. Install the new spool valve section with new O-rings/seals. Torque the tie rods to the manufacturer's specification.

5. 5

   Reassemble and Clear Codes

   Reconnect the electrical connections, reinstall the metal access panel, clear the fault codes via the tractor's terminal, and test the front power lift / auxiliary hydraulic functions.