Fendt 1.2.46 – EDC (Electronic Diesel Control) Engine Control Module: Bus system - Enhanced control bus, transmission bus, EDC bus — CAN-bus message fault.

This code indicates a CAN-bus communication failure. The data communication between the EDC (Electronic Diesel Control) engine control module, the transmission bus (G-BUS), and the enhanced control bus (Comfort-BUS) has been interrupted or restricted. The system registers a "Vehicle CAN Busoff" state. The tractor enters a restricted operating mode (auxiliary operation). The operator will experience a loss of enhanced features, and engine control is reduced to basic foot throttle availability only.

• 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 Favorit 900 series (chassis number 23/3001 and up)
• Fendt Farmer 400 series
• Fendt Favorit 700 series
• Fendt 900 Vario COM III series (models 916, 920, 924, 926, 930 Vario)
• Fendt 800 Vario series
• Fendt 300 Vario series

1. 1

   Diagnostic Tool Verification: Connect to the tractor's diagnostic connector (X412) using the FENDIAS or SERDIA diagnostic software to read live parameters from the Engine and Injection pump control modules.

2. 2

   Power and Ground Check: Verify the voltage supply (+Ub) to the EDC control module. Check the main EDC relay (K020 / Ub30) to ensure the contacts are opening and closing properly and that the battery is not discharging.

3. 3

   Wiring and Circuit Inspection: Consult the circuit diagrams for 'EDC engine control', 'transmission bus', and 'enhanced control bus'. Inspect the physical CAN lines connecting the EDC control module (A021) to the EST control module (A002).

4. 4

   Connector Inspection: Check the main EDC connectors (e.g., Connector X692 for UB 30 on the EDC control unit, typically located in the cab on the right mudguard) for corrosion, backed-out pins, or moisture.

1. 1

   Isolate the Battery

   Disconnect the tractor's battery before performing electrical repairs to prevent short circuits.

2. 2

   Inspect and Repair Wiring

   Trace the CAN-bus wiring harness between the EDC module, the transmission bus, and the comfort bus. Look for chafing, breaks, or melted insulation. Repair any damaged wires using proper CAN-bus splicing techniques (maintaining the twist in the wire pairs).

3. 3

   Clean Connectors

   Disconnect the EDC and EST module connectors. Treat the rubber seals with silicone to prevent damage, and use a dedicated contact cleaner on the pins. Ensure all locking tabs are secure upon reconnection.

4. 4

   Replace Faulty Relays/Fuses

   If the diagnostic checks revealed a failure in the power supply circuit, replace the main EDC relay (K020) or blown microfuses in the electronics box.

5. 5

   Module Replacement (If Necessary)

   If the wiring harness and power supplies are fully intact but the CAN-bus message fault persists, the EDC control unit itself has likely suffered an internal communication driver failure. Replace the EDC module.

6. 6

   EOL Programming

   If the EDC control unit is replaced, or if the communication driver initialization error requires a reset, perform End-Of-Line (EOL) reprogramming using the Fendt diagnostic terminal to restore full Tractor Management System (TMS) functionality.