Fendt 01.1.37 – Immobiliser Control Unit: Performance curve not sent to EDC

A data transfer failure where the power/performance curve data from the Engine Control Unit (EDC) is missing or not being successfully transmitted to the Immobiliser Control Unit for comparison. Without this data match, the immobiliser cannot validate the engine management system, which can prevent the tractor 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III, SCR, S4)
• Fendt 800 Vario (COM III, S4)
• Fendt 900 Vario (COM III, SCR, S4)

1. 1

   Connect the FENDIAS or SERDIA service diagnostics program to read the fault log and test the CAN bus communication between the Immobiliser ECU (A077/B083) and the Engine Control Unit (A051/A127/A099).

2. 2

   Verify that the ignition key is being recognized. Look for accompanying fault codes like 01.1.31 (Invalid transponder data) or 01.1.32 (Ignition key without transponder recognised), which would point to a key issue rather than an ECU data issue.

3. 3

   Check the physical wiring harness at the immobiliser separation point (X1494) for loose pins, corrosion, or broken wires.

1. 1

   Access the Module

   Ensure the tractor is turned off. Locate the B083 Immobiliser control unit. It is located inside the cab, on the left side of the steering column. You must remove the steering column side panel to access it.

2. 2

   Inspect Separation Point X1494

   Disconnect and inspect the X1494 connector (the main separation point on the B083 unit). Clean the contacts and repair any damaged wiring.

3. 3

   Software Reprogramming (EOL)

   If the wiring is intact, the missing performance curve is a software/data loss issue. Using the SERDIA/FENDIAS diagnostic tool, perform an EOL (End of Line) programming procedure to rewrite the equipment data and performance curve to the modules.

4. 4

   Key Teach-in

   After EOL programming, you must teach in the vehicle key(s) again using the diagnostic software.

5. 5

   Module Replacement

   If the immobiliser ECU refuses to accept the EOL programming or fails to communicate entirely, the A077/B083 module must be replaced and reprogrammed.