Fendt 8.3.40 – A004 - Control Console / Control Panel ECU: A004 - Rear power lift quick lift switch — Fault in switch / A004 contact

The system has detected a signal fault, short, or internal failure within the quick lift switch located on the cab's control console. The tractor's Electrohydraulic Power Control (EPC) disables the internal cab controls for the rear hitch, allowing operation only via external fender buttons.

• 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Farmer 400
• 409
• 410
• 411
• 412
• Fendt 700 Vario (COM III)
• Favorit 700
• 711
• 712
• 714
• 716
• 718
• Fendt 800 Vario (COM III)
• 815
• 817
• 818
• 820
• Fendt 900 Vario (COM III)
• Favorit 900
• 916
• 920
• 924
• 926
• 930

1. 1

   Verify external operation by testing the rear power lift using the external fender buttons to isolate the issue to the cab's A004 control console circuit

2. 2

   Inspect the rapid lift control switch on the A004 console for physical damage, sticking mechanisms, or liquid intrusion

3. 3

   Check the K-Bus cabling and wiring harness connecting the A004 control console to the A014 ECU for pinched wires, line discontinuities, or loose connector pins

4. 4

   Verify the CAN-Bus voltage supply on fuse board A013 (fuses F040, F041) is intact

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the tractor's battery to prevent electrical shorts while working on the CAN-bus modules.

2. 2

   Access the Console

   Carefully remove the trim panels to access the underside/internals of the A004 control console in the cab.

3. 3

   Test the Switch

   Disconnect the wiring harness from the rear power lift quick lift switch. Use a multimeter to test the switch for continuity. If the switch fails to show proper open/closed states when toggled, the internal contacts are burnt or broken.

4. 4

   Replace Component

   If the switch fails the continuity test, replace the quick lift switch (or the affected console sub-assembly, depending on the exact console revision).

5. 5

   Repair Wiring

   If the switch tests fine, use a multimeter to trace the K-Bus wiring from the A004 console to the A014 ECU. Repair any broken wires or clean corroded connector pins.

6. 6

   Reassemble and Clear Codes

   Reconnect the wiring harness, reassemble the console, and reconnect the battery. Turn on the ignition, navigate to the tractor's terminal, and clear the stored 8.3.40 fault code from the memory.

7. 7

   Final Test

   Operate the rear power lift from inside the cab to confirm the repair is successful.