Fendt 1.2.2D – EST Control Module (A002) / EDC Control Module (A021): CAN signal failure or interrupted connection on the Transmission BUS

The tractor's enhanced control unit is failing to communicate properly with the engine control unit over the CAN bus network. The tractor will lose enhanced engine control features, optimum engine control is no longer possible, and the machine will typically default to a restricted operating mode where only the foot throttle is available.

• 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 series
• Fendt Favorit 700 series
• Fendt Favorit 900 series
• Fendt 300 Vario series
• Fendt 400 Vario series
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series

1. 1

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

2. 2

   Inspect the physical wiring harness on the Transmission BUS between the A002 and A021 modules for chafed wires, broken connections, or corrosion at the connector pins.

3. 3

   Connect the AGCO 2x4 CANUSB diagnostic scanner (using FENDIAS software) to read live data and confirm if the communication drop is isolated to these two modules or if the entire Transmission BUS is down.

1. 1

   Power Down

   Turn off the ignition and disconnect the battery before servicing the electrical system to prevent short circuits.

2. 2

   Fuse Replacement

   If fuses F040 or F041 on board A013 are blown, replace them and retest. If they blow again immediately, trace the circuit for a short to ground.

3. 3

   Harness Repair

   If the diagnostic tests reveal an open or shorted wire between the A002 and A021 modules, repair or replace the damaged section of the CAN bus wiring harness. Clean any corroded pins with electrical contact cleaner and apply dielectric grease.

4. 4

   Module Testing/Replacement

   If the wiring and power supplies are fully intact but the CAN signal is still failing to transmit from A002 to A021, one of the modules has an internal failure. Use the diagnostic scanner to determine which module is unresponsive.

5. 5

   EOL Programming

   If either the A002 (EST) or A021 (EDC) module must be replaced, the new module will require End-of-Line (EOL) programming via the FENDIAS diagnostic tool to sync it with the tractor's specific configuration.