Fendt 01.1.3A – A077 - Immobiliser ECU: U001 - Immobiliser aerial faulty / signal line faulty

The immobiliser antenna is defective or its wiring is compromised, meaning the transponder in the ignition key cannot be read. As a result, the vehicle cannot be started.

• 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III, SCR, Gen7)
• Fendt 800 Vario (COM III, S4, SCR)
• Fendt 900 Vario (COM III, Gen7)

1. 1

   Test the Key: Try starting the tractor with a spare ignition key. If the spare works, the transponder chip inside the primary key may be damaged rather than the aerial itself.

2. 2

   Inspect the Wiring: Check the signal line between the U001 Immobiliser aerial and the A077 Immobiliser ECU.

3. 3

   Check the Connector: Locate separation point/connector X1693 (Pin 1 and Pin 2 correspond to the aerial). Check for loose pins, corrosion, or broken wires.

1. 1

   Disconnect battery

   Disconnect the tractor's battery to prevent electrical shorts.

2. 2

   Locate immobiliser aerial

   Locate the U001 Immobiliser aerial, which is mounted on the steering column directly at the ignition switch.

3. 3

   Remove steering column panel

   Remove the steering column panel/cowling to access the ignition switch assembly.

4. 4

   Disconnect aerial

   Disconnect the aerial at connector X1693.

5. 5

   Remove faulty aerial

   Remove the faulty immobiliser aerial ring from around the ignition barrel.

6. 6

   Install new aerial

   Install the new OEM immobiliser aerial and plug it into connector X1693.

7. 7

   Reinstall panel

   Reinstall the steering column panel.

8. 8

   Reconnect battery and test

   Reconnect the battery, clear the fault codes using the diagnostic terminal, and test the ignition to ensure the transponder is successfully read and the engine starts.