Fendt 1.2.2E – A002 / A021: A002, A021 - Enhanced control module, EDC control module, transmission bus — CAN signal fault.

A CAN (Controller Area Network) signal communication failure on the transmission bus between the Enhanced Control Module (A002) and the Electronic Diesel Control (EDC) Engine Control Module (A021). The tractor will typically enter a restricted operating mode (limp mode) with limited engine power, or emergency mode, to protect the drivetrain.

• 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 400 Vario series (409, 410, 411, 412)
• Fendt Favorit / Vario 700 series (711, 712, 714, 716)
• Fendt Favorit / Vario 800 series (815, 817, 818)
• Fendt Favorit / Vario 900 series (916, 920, 924, 926, 930)
• Fendt 300 Vario series

1. 1

   Check the power supply and fuses for the CAN bus circuit board (specifically the A013 fuse board) and ensure the EDC control module is receiving proper +UB voltage.

2. 2

   Inspect the physical wiring harness on the 'Transmission Bus' circuit between the A002 and A021 modules for chafed wires, corrosion, or loose pins.

3. 3

   Measure the CAN bus resistance to ensure terminating resistors are intact (typically 60 ohms across CAN High and CAN Low with battery disconnected).

4. 4

   Connect the FENDIAS or Serdia diagnostic tool to verify if the A021 EDC module can be identified on the network.

1. 1

   Disconnect Power

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

2. 2

   Inspect the Harness

   Locate the A002 Enhanced Control Module and the A021 EDC Control Module. Disconnect the harness at both ends and perform a continuity test on the CAN High and CAN Low lines.

3. 3

   Repair Wiring

   If resistance is high or continuity is broken, repair or replace the damaged section of the transmission bus wiring harness.

4. 4

   Check Module Grounds

   Ensure both the A002 and A021 modules have clean, tight ground connections to the chassis.

5. 5

   Test with Known Good Module

   If the wiring, fuses, and grounds are perfect, one of the modules has a failed internal CAN transceiver. Replace the module (EOL reprogramming will be necessary).

6. 6

   Clear Codes

   Reconnect the battery, turn on the ignition, and use the FENDIAS scanner to clear the 1.2.2E fault code. Perform a test drive to ensure the restricted power mode is lifted.