Fendt 9.3.15 – EPC C: Pushbutton ext. front power lift 'lower' — Signal line fault

The control unit has detected a disrupted signal, an open circuit, a short circuit, or a faulty power supply on the circuit belonging to the external pushbutton used to lower the front linkage, triggering a 'Control locked' state.

• 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 300 and 400 Vario (COM III)
• Fendt Favorit 500, 700, 800, and 900 series
• Fendt 700, 800, and 900 Vario series (COM III and earlier)

1. 1

   Inspect the external 'lower' pushbutton located on the front linkage for physical damage, sticking (button double operation), or water ingress.

2. 2

   Trace the signal line from the external switch back to the EPC C module. Look for pinched wires, chafing, or corroded connector pins.

3. 3

   Disconnect the switch and use a multimeter to verify that the switch is receiving its reference voltage.

4. 4

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

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to prevent short circuits during the repair.

2. 2

   Access the Switch

   Locate the faulty external front power lift 'lower' pushbutton on the front linkage housing/grille area.

3. 3

   Disconnect

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

4. 4

   Remove the Switch

   Depress the retaining clips or unscrew the retaining nut (depending on the exact switch housing) and push the old switch out of its mounting panel.

5. 5

   Install the New Part

   Insert the replacement OEM pushbutton into the mounting hole until it clicks or is securely fastened.

6. 6

   Reconnect

   Plug the electrical connector back into the switch, ensuring the weather seal is seated correctly to prevent future moisture ingress.

7. 7

   Restore Power & Clear Codes

   Reconnect the battery and turn on the ignition. Use the tractor's Varioterminal or the FENDIAS diagnostic tool to clear the stored 9.3.15 fault code from the EPC C memory.

8. 8

   Test Operation

   Test the front power lift using the newly installed external 'lower' button to confirm the linkage operates smoothly and the fault does not return.