Fendt 01.1.34 – A077 - Immobiliser ECU: B083 - Immobiliser control: No response from immobiliser control

Communication failure where the immobiliser system is not responding to the tractor's main control network. Because the immobiliser cannot verify a valid transponder key, the underlying condition prevents the engine from starting.

• 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 900 Vario (COM III generation)
• Fendt 700 - 900 Vario SCR series
• Fendt 300 Vario
• Fendt 724 S4

1. 1

   Verify that the ignition key has a valid transponder and is not physically broken, as a damaged key will fail to send the RFID signal.

2. 2

   Check for related fault codes that narrow down the issue (e.g., 01.1.30-01.1.32 for key issues, 01.1.3A for aerial faults, 01.1.35 for teach-in mode, or 01.1.36 for EDC communication).

3. 3

   Inspect the U001 Immobiliser aerial (the ring antenna around the ignition barrel) and its wiring harness for physical damage or loose connections.

4. 4

   Test the CAN bus wiring harness and communication lines between the A077 Immobiliser ECU, the A050 Basic Control ECU, and the Engine ECU for continuity and proper voltage.

1. 1

   Resolve Wiring/Hardware Faults

   If the diagnostic checks reveal a damaged U001 immobiliser antenna or broken wiring, replace the antenna or repair the harness.

2. 2

   Key Teach-in Procedure

   If the key transponder has lost sync or a new key is being used, connect the FENDIAS diagnostic tool. Navigate to the immobiliser settings and execute the 'Teach in vehicle key' procedure.

3. 3

   Module Synchronization (EOL Programming)

   If the A077 Immobiliser ECU or the Engine ECU (A051/A099) was replaced or suffered data corruption, the modules must be paired. Use FENDIAS to perform End-of-Line (EOL) programming to re-establish the immobilisation communication exchange and send the performance curve to the EDC.

4. 4

   Software Bypass (Non-OEM)

   In cases where hardware replacement is not viable, utilize tools like KessV2 alongside Fendias to flash an 'immo off' or custom immobiliser activation file to the Deutz EDC17 controller.