Fendt 6.1.11 – A004 - ECU, Control Panel: A004 - ECU, control panel; Rear PTO auto mode button.

A 'Signal fault' originating from the Rear PTO automatic mode key/button, indicating an electrical or mechanical fault such as the button being stuck or pressed for more than 30 seconds. As a safety measure, the PTO disengages and the automatic mode is forced OFF.

• 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
• 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 series
• Fendt Favorit 700 and 900 series
• 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

   Inspect the Rear PTO automatic mode button on the A004 control console for physical damage, debris, or sticking (a button stuck for more than 30 seconds triggers this fault)

2. 2

   Test the button's electrical continuity to ensure it opens and closes the circuit correctly when pressed and released

3. 3

   Inspect the wiring harness and connectors between the PTO button and the A004 control panel for chafing, corrosion, or line discontinuity

4. 4

   Verify the voltage supply for the A004 control console on fuse board A013 (check fuses F040 and F041) to rule out broader console communication issues

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Access the Control Panel

   Carefully remove the trim surrounding the A004 control console to access the rear wiring of the PTO switches.

3. 3

   Test/Clean the Switch

   If the button is mechanically sticking, clean the housing with electrical contact cleaner. If the switch fails a multimeter continuity test, it must be replaced.

4. 4

   Repair Wiring

   If the wiring harness shows signs of damage or discontinuity between the switch and the A004 ECU, repair the broken wires or replace the affected harness section.

5. 5

   Replace Components

   If the button is functioning correctly and the wiring is intact, the fault may lie within the A004 Control Console itself, requiring replacement or professional circuit board repair.

6. 6

   Clear Codes and Test

   Reconnect the battery, start the tractor, and clear the fault codes using the FENDIAS diagnostic tool. Engage the Rear PTO auto mode to verify the repair. (Note: In an emergency before repair, the PTO can sometimes be engaged by pressing the emergency key in the cab for 5 seconds).