Fendt 8.3.42 – A004 Control Console: A004 - Rear EPC, hitch function — Fault in switch/A004 contact

This code indicates an electrical fault, signal line fault, or mechanical failure within the hitch control button/switch located on the main control console. When this fault is triggered, the tractor's system locks out the rear Electronic Power Control (EPC) to prevent unintended movement, resulting in the rear hitch function becoming completely non-operational.

• 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 Vario Series
• Fendt Favorit 700 Series
• Fendt Favorit 900 Series
• Fendt 300 Vario
• Fendt 400 Vario
• Fendt 700 Vario
• Fendt 800 Vario
• Fendt 900 Vario
• 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 the CAN (K-bus) Communication: Verify if there are accompanying CAN bus faults between the A004 (Control Console) and A005 (Rear EPC E-box). If communication codes (like 0.0.13 or 0.0.18) are present, the issue may be a wiring or fuse problem rather than the switch itself.

2. 2

   Inspect Fuses: Check the power supply for the CAN Bus on printed circuit board A013 (specifically fuses F040 and F041).

3. 3

   Test the Switch Contact: Access the 'Electrohydraulic power lift control' circuit diagram (often Sheet 25 in the OEM manual) to identify the pinouts for the hitch button. Use a multimeter to test the hitch button on the A004 console for continuity when pressed.

4. 4

   Check for Sticking Buttons: Ensure the hitch button is not physically jammed or stuck in the depressed position due to dirt or debris.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical shorts during console disassembly.

2. 2

   Clean the Console

   Before replacing parts, use compressed air and electrical contact cleaner around the hitch button on the A004 console. A stuck contact due to agricultural debris is a common cause of this fault.

3. 3

   Access the A004 Console

   Carefully remove the trim panels surrounding the right-hand A004 control console/armrest.

4. 4

   Test/Replace the Switch

   If the hitch switch is a modular component on your specific Vario model, disconnect its wiring harness and replace the faulty switch.

5. 5

   Console Replacement/Repair

   On many Fendt models, the A004 control console is a sealed printed circuit board unit. If the internal switch contact has failed and cannot be individually desoldered/replaced, the entire A004 control console must be sent out for specialized circuit board repair or replaced entirely.

6. 6

   Reassembly and Calibration

   Reconnect the battery. If the A004 console was replaced, you may need to perform an End-of-Line (EOL) programming/calibration using FENDIAS (Fendt's diagnostic software) to pair the new console with the tractor's CAN bus system.