Fendt 1.2.DE – A002 Enhanced Control Module / A021 EDC Control Module: Propagation time of CAN communication missing

There is an interruption, timeout, or complete failure in the CAN bus communication network between the tractor's enhanced control module (A002) and the engine control module (A021), causing the tractor to enter a restricted operating mode (limp mode).

• 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
• Farmer 400 Vario Series: 409, 410, 411, 412
• Favorit 700 / 700 Vario Series: 711, 712, 714, 715, 716, 717
• Favorit 900 / 900 Vario Series: 916, 920, 924, 926, 930
• 800 Vario Series: 815, 817, 818
• COM III Vario Models: 300, 400, 700, 800, and 900 series

1. 1

   Verify Voltage and Fuses: Check the main voltage supply to the CAN-Bus on fuse board A013. Verify that the fuses supplying the EDC control module (A021) are not blown.

2. 2

   Check Connectors: Inspect Connector X031 (at the A002 module) and Connector X048 (at the A021 module) for loose pins, corrosion, or moisture ingress.

3. 3

   Measure CAN-Bus Continuity: Using an adaptor box and multimeter, test continuity from EST A002, Pin 4 (Connector X031) to EDC A021, Pin 11 (Connector X048), and from EST A002, Pin 5 (Connector X031) to EDC A021, Pin 12 (Connector X048).

4. 4

   Check for Shorts: Test the CAN-Bus wiring for short circuits to ground or voltage supply failures.

1. 1

   Disconnect Power

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

2. 2

   Restore Wiring/Connections

   If the diagnostic continuity test fails, locate the break or short in the wiring harness between A002 and A021. Repair the wiring discontinuity or replace the damaged section of the CAN-Bus harness.

3. 3

   Replace Fuses/Fuse Board

   If the fuses on board A013 are blown, replace them. If the fuse board itself has an internal short or failure, replace the fuse board.

4. 4

   Replace Connectors

   If Connector X048 or X031 is damaged, splice in a new OEM connector repair kit.

5. 5

   Module Replacement (If Necessary)

   If wiring, fuses, and connectors all test perfectly but the CAN communication is still missing, the A021 EDC Control Module or A002 Enhanced Control Module has suffered an internal hardware failure. Replace the faulty module.

6. 6

   Reprogramming

   If a control module (A002 or A021) is replaced, EOL (End of Line) reprogramming will be necessary using the FENDIAS / Serdia diagnostic software to match the module to the tractor's specific engine and transmission configuration.