Fendt 06.1.E2 – A050 - ECU, basic control unit (EXT): Checksum error for the rear PTO pulse width (PW) increase

The parameter data governing how the rear Power Take-Off (PTO) engages (specifically the electrical pulse width modulation that controls the clutch engagement curve) has become corrupted or failed a mathematical checksum validation. The tractor's electronic system will ignore the corrupted parameters and default to standard, pre-programmed safety values for the rear PTO.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 200 V/F/P Vario (207, 208, 209, 210, 211)
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III / SCR)
• Fendt 800 Vario (COM III / SCR)
• Fendt 900 Vario (COM III / SCR / Gen6)
• Fendt 916 Vario
• Fendt 919 Vario
• Fendt 920 Vario
• Fendt 922 Vario
• Fendt 924 Vario
• Fendt 926 Vario
• Fendt 927 Vario
• Fendt 930 Vario
• Fendt 933 Vario
• Fendt 936 Vario
• Fendt 939 Vario
• Fendt 942 Vario

1. 1

   Verify PTO Operation: Engage the rear PTO to see if it operates abruptly. The system defaults to standard values, so the PTO may still function but lack the smoothed engagement curve.

2. 2

   Check ECU Power & Ground: Verify the supply voltages (KL30, KL15) and earth supply (KL31) to the A050 basic control unit. Voltage spikes or drops during startup can cause EEPROM memory corruption.

3. 3

   Check CAN Bus Integrity: Inspect the wiring harness and connectors at the A050 ECU (specifically separation points X169 and X1403) for corrosion or loose pins that might interrupt G-bus communication.

1. 1

   Connect diagnostic interface

   Connect the AGCO CANUSB diagnostic interface and launch the FENDIAS diagnostic software.

2. 2

   Establish communication

   Establish communication with the A050 - ECU, basic control unit.

3. 3

   Perform EOL programming

   Perform an EOL programming flash on the A050 ECU (requires software version 7.60 or higher) to rewrite the corrupted PTO parameters and restore the correct checksums.

4. 4

   Clear fault codes

   Clear the inactive fault codes and cycle the tractor's ignition key.

5. 5

   Test PTO engagement

   Test the rear PTO engagement to ensure the pulse width increase operates smoothly and the fault code does not return.

6. 6

   Repair or replace ECU

   If the EOL programming fails, or if the code returns immediately upon cycling the key, the A050 ECU has suffered an internal EEPROM hardware failure and must be repaired or replaced.