Fendt 9.1.50 – A002 ECU: Spool valve fault (Y019 - Auxiliary control valve)

The Y019 auxiliary control valve cannot be identified via the bus line, meaning there is no signal from the valve communicating with the tractor's network. As a direct consequence, no valve operation is available, and the system automatically forces the valve to move into a neutral, fail-safe position.

• 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 Farmer 400
• Fendt Favorit 700
• Fendt Favorit 900
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)

1. 1

   Check CAN Bus Power Supply: Check printed circuit board A013, specifically inspecting fuses F040 and F041.

2. 2

   Check Signal Flow: Verify the signal flow diagram for the A002 ECU, specifically testing CAN II pins 4 and 5 for continuity and proper voltage.

3. 3

   Inspect Wiring Harness: Consult the wiring diagram for the 'FRONT POWER LIFT / VENDI' (referenced as Sheet 28 or Sheet 22/26 depending on the specific tractor model's manual). Look for broken wires, chafing, or corroded connector pins between the A002 ECU and the Y019 valve.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to ensure safety while working on the electrical and hydraulic systems.

2. 2

   Fuse Inspection

   Locate circuit board A013. Test and replace fuses F040 or F041 if they are blown. Re-test the system; if the code clears, the repair is complete.

3. 3

   Harness Testing

   Disconnect the electrical connector at the Y019 Auxiliary control valve and the A002 ECU. Use a multimeter to perform a continuity test on the CAN II lines (pins 4 and 5). Repair any open circuits or shorts to ground in the wiring harness.

4. 4

   Valve Replacement

   If the fuses are intact, the wiring harness tests good, and the A002 ECU is outputting the correct CAN signal, the internal electronics of the Y019 spool valve have failed.

5. 5

   Hydraulic Depressurization

   Before removing the Y019 valve, ensure all hydraulic pressure is relieved from the front power lift system.

6. 6

   Swap Valve

   Unbolt the Y019 auxiliary control valve from the valve block, taking care to catch any residual hydraulic fluid. Install the replacement valve with new O-rings/seals.

7. 7

   Reassembly and Clearing

   Reconnect the electrical harness, restore battery power, and use the FENDIAS diagnostic tool (or the tractor's onboard Variotronic terminal) to clear the stored 9.1.50 fault code. Test the front power lift for proper operation.