Fendt 01.1.04 – A002 (Enhanced Control ECU) / A050 (Basic Control ECU): Checksum error TMS

Data corruption or checksum mismatch within the ECU's EPROM memory specifically related to the Tractor Management System (TMS) parameters. As a result, TMS driving is not possible and the tractor defaults to a restricted operating mode.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 200 V/F/P Vario series
• 300 Vario (including COM III)
• 400 Vario (including COM III)
• 700 Vario (including COM III)
• 800 Vario (including COM III)
• 900 Vario (including COM III)

1. 1

   Verify the symptom: Confirm that manual foot-throttle operation still works while TMS is disabled

2. 2

   Check for concurrent CAN bus or voltage faults that might have caused a memory corruption during operation

3. 3

   Inspect the physical connections at the ECU (specifically the X031 separation point on the A002 ECU) for corrosion or loose pins

1. 1

   Perform EOL programming

   The official remedy listed in the Fendt service manuals is EOL (End-Of-Line) programming.

2. 2

   Connect diagnostic tool

   Connect the FENDIAS (Fendt Diagnostic System) or EST dealer tool to the tractor.

3. 3

   Reprogram ECU

   Reprogram/reflash the A002 or A050 ECU with the correct standard parameters for the specific tractor chassis.

4. 4

   Clear codes and test

   Clear the fault codes and test the TMS operation.

5. 5

   Replace ECU if necessary

   If the EPROM cannot be overwritten or fails to hold the EOL programming (e.g., a fatal memory failure), the A002/A050 ECU box must be replaced and subsequently programmed.