Fendt 1.2.CD – EDC Control Module (A021) / Pump Control Unit (A020): Fault in propagation time of CAN communication between pump control unit and EDC control module

CAN bus network messages traveling between the engine's main computer and the injection pump's dedicated controller are delayed, missing, or experiencing timing issues. This causes the tractor's system to enforce a 'Restricted Power' or 'Reduced speed, reduced engine power' state to protect the engine.

• 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 Vario Series
• Farmer 400 Vario series
• Farmer 700 Vario series
• Farmer 800 Vario series

1. 1

   Check the CAN-BUS wiring harness specifically between the EDC Control Module (A021) and the Pump Control Unit (A020) for breaks, high resistance, or shorts

2. 2

   Verify the voltage supply (+UB) and earth/ground connections to both the A021 and A020 modules, as a voltage drop can cause CAN propagation delays

3. 3

   Inspect the connectors at the injection pump and the EDC module for corrosion, moisture, or backed-out pins

4. 4

   Consult the 'EDC Control' electric diagram to trace the exact CAN High and CAN Low pinouts between the two modules

1. 1

   Turn off the ignition and disconnect the battery

   Turn off the ignition and disconnect the battery to prevent electrical spikes during harness testing.

2. 2

   Locate the EDC Control Module and Pump Control Unit

   Locate the EDC Control Module (A021) and the Pump Control Unit (A020), which is mounted directly on the electronic injection pump.

3. 3

   Repair or replace the wiring harness

   If the diagnostic checks reveal a damaged CAN wire between A021 and A020, repair the wiring harness using proper CAN-bus splicing techniques (maintaining the twist in the wires) or replace the affected harness section.

4. 4

   Clean electrical connections

   Apply electrical contact cleaner to the plugs on both modules and ensure they seat firmly.

5. 5

   Replace the faulty module

   If the wiring, power, and grounds are perfectly intact, the fault lies internally within the CAN transceiver of either the Pump Control Unit (A020) or the EDC Control Module (A021). The faulty module must be replaced. (Note: Replacing the EDC A021 will require EOL (End of Line) reprogramming via FENDIAS software).

6. 6

   Clear fault codes and test drive

   Reconnect the battery, clear the fault codes using the Fendt terminal or FENDIAS diagnostic tool, and test drive the tractor to ensure full engine power is restored and the code does not return.