Fendt 05.1.00 – A002 - ECU, enhanced control: EEPROM checksum error / Control unit fault / E-Box faulty

The internal memory (EEPROM) of the control unit has detected corrupted data, mismatched configuration parameters, or a physical hardware failure within the memory chip itself.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 300 Vario series
• Fendt 400 Vario series (e.g., 411-415)
• Fendt 700 Vario series (e.g., 712-718)
• Fendt 800 Vario series (e.g., 818-820)
• Fendt 900 Vario series (COM II, COM III, SCR, Gen6)

1. 1

   Verify the voltage supply to the CAN-Bus and the A002 ECU by checking the A013 fuse board for stable power.

2. 2

   Check the wiring harnesses and CAN bus connections (e.g., the X031 connector) to ensure the A002 ECU is communicating properly with the basic control unit (A050) and engine control modules.

3. 3

   Connect the FENDIAS diagnostic software to verify communication with the A002 ECU and check the ECU load counter.

1. 1

   Attempt Reprogramming

   Connect the FENDIAS diagnostic tool to the tractor. Attempt to perform an EOL programming procedure to reflash the EEPROM and rewrite the corrupted configuration data.

2. 2

   Verify Functions

   If the EOL programming is successful, clear the fault codes and test the enhanced control functions (4WD, differential lock, PTO) to ensure the checksum error does not return.

3. 3

   Replace the E-Box

   If the FENDIAS tool cannot communicate with the E-Box, or if the EOL programming fails (indicating a hard physical failure of the EEPROM chip), the A002 E-Box must be replaced.

4. 4

   Hardware Swap

   Disconnect the tractor's battery. Locate the E-Box, disconnect the wiring harnesses, and remove the faulty unit. Install the replacement E-Box.

5. 5

   Flash the New Unit

   A new E-Box is blank. Reconnect the battery and use the FENDIAS software to flash-program the new E-Box with the specific software and EOL parameters matching the tractor's chassis number and optional equipment.