Fendt 1.2.21 – EST Control Module (A002): CAN-Bus communication failure

The Fendt EST (Enhanced Control Module / Transmission Control Module) is not connected, or the CAN connection to the transmission bus and the EDC (Electronic Diesel Control) is interrupted.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
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• 924 Vario
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• Farmer 400 Vario
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• 300, 400, 700, 800, and 900 Vario (COM III) series

1. 1

   Check the CAN-Bus voltage supply on fuse board A013, specifically fuses F040 and F041.

2. 2

   Inspect the CAN-Bus wiring harness for short circuits to ground or open circuits between the EST Control Module (A002) and the EDC Control Module (A021).

3. 3

   Inspect the specific pins on Connector X031 (at the EST module) and Connector X048 (at the EDC module) for corrosion, backed-out pins, or moisture.

1. 1

   Connect diagnostic tool

   Turn the tractor's ignition to 'ON' and connect a diagnostic adaptor box if available.

2. 2

   Inspect and replace fuses

   Locate fuse board A013 and inspect fuses F040 and F041. If either is blown, replace it and retest the system. If the fuse blows again immediately, trace the circuit for a short to ground.

3. 3

   Test CAN-Bus continuity

   If the fuses are intact, use a multimeter to test the CAN-Bus communication lines. Measure continuity from the EST Control Module A002, Pin 4 (on Connector X031) to the EDC Control Module A021, Pin 11 (on Connector X048). Then measure continuity from the EST Control Module A002, Pin 5 (on Connector X031) to the EDC Control Module A021, Pin 12 (on Connector X048).

4. 4

   Repair wiring and connectors

   Repair any broken wires or replace damaged connector terminals found during the continuity test.

5. 5

   Replace defective control module

   If the wiring, connectors, and fuse board A013 are all in good working order, the fault is internal to either the EST Control Module (A002) or the EDC Control Module (A021). Replace the defective module.

6. 6

   Reprogram control module

   Perform EOL (End of Line) reprogramming using the FENDIAS diagnostic software to restore full functionality to the newly installed control module.