Fendt 8.3.18 – Rear EPC (Electrohydraulic Power Control): "Raise" rear power lift external pushbutton, cab, right rear — Signal line fault.

The tractor's control system has detected an electrical fault (such as an open circuit, short circuit, or a stuck/faulty button) on the signal line for the external "Raise" button located on the right rear fender/cab exterior. The system triggers a "Control locked" state for safety.

• 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
• Farmer 400 Vario series
• Favorit 700 and 900 series
• Fendt 300, 400, 700, 800, and 900 Vario series (including COM III models)

1. 1

   Inspect the right rear external 'Raise' pushbutton (S027) for physical damage, sticking (a double operation or stuck button will trigger this fault), or water/debris ingress.

2. 2

   Examine the wiring harness and the connector at the switch for corrosion, broken wires, or loose connections.

3. 3

   Using a multimeter, check the signal line for continuity back to the Rear EPC module. Verify there is no short to ground or short to voltage on the signal wire.

4. 4

   Test the switch itself for proper continuity when pressed and released to confirm if the internal contacts have failed.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to ensure the electrical system is safe to work on.

2. 2

   Access the Switch

   Locate the faulty S027 "Raise" pushbutton on the right rear fender/cab exterior.

3. 3

   Disconnect

   Unplug the electrical harness connector from the back of the switch.

4. 4

   Repair or Replace

   If the diagnostic checks revealed a wiring issue, repair the damaged section of the harness. If the switch is faulty, unclip or unscrew the switch housing from the fender mounting and install the new OEM replacement switch.

5. 5

   Reconnect

   Plug the electrical harness back into the new switch, ensuring the connector is fully seated and weather-sealed.

6. 6

   System Reset

   Reconnect the battery. Perform a "cold start" (turn the ignition on, start the tractor, and let the systems initialize). The EPC module requires a trouble-free cold start to clear the control lock and restore functionality.

7. 7

   Verify Operation

   Test the rear power lift using the newly installed external button to confirm the linkage raises correctly.