Fendt 00.0.04 – A050 - ECU, basic control unit (or A002 - ECU, enhanced control): Transmission bus fault, no setpoint value to actuator unit

The central control unit has lost CAN bus communication with the transmission actuator, or the required setpoint signal is missing. Consequently, the tractor's transmission functions become non-operational, and there is no display.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 200 Vario (V, F, P, S)
• 300 Vario (COM III)
• 400 Vario (COM III)
• 500 Vario
• 700 Vario (COM III, SCR)
• 800 Vario (COM III)
• 900 Vario (COM III, S4, Gen6)
• 1000 Vario

1. 1

   Check the 'Electronics voltage supply' circuit diagram and inspect the transmission CAN bus communication lines between the A050 ECU and the transmission actuator unit for continuity, shorts, or breaks.

2. 2

   Verify the power (+UB) and ground connections (Earth KL31, Switched voltage KL15) to the A050 ECU.

3. 3

   Test the A050 ECU using a Fendt 160-pin adapter box to verify pinout signals.

4. 4

   Verify fault memory using FENDIAS diagnostic software, as clearing codes from the A007 Instrument Panel will not clear them from the A050 ECU.

1. 1

   Connect Diagnostics

   Connect the FENDIAS diagnostic tool to confirm the 00.0.04 fault is currently active in the A050 ECU.

2. 2

   Inspect Wiring

   Physically inspect the wiring harness and connectors between the A050 ECU and the transmission actuator. Repair any damaged wiring or corroded pins.

3. 3

   EOL Programming

   Use FENDIAS to reflash/reprogram the A050 Basic Control Unit (End of Line programming).

4. 4

   ECU Repair/Replacement

   If EOL programming fails or the ECU has suffered an internal EEPROM/hardware failure, the A050 unit must be removed.

5. 5

   Reinstallation

   If replacing or repairing the A050 ECU, it must be re-paired with the A077 Immobilizer ECU and A099 Engine Control Unit so the chassis numbers and performance curves match. Perform a final EOL programming and clear the fault codes.