CLAAS Id78B5h / 78B5h (845) – TR2 (A57-2) Transmission Module: Automatic gear shifting disconnected during a sequence CSM

The automatic gear shifting function was unexpectedly interrupted or disconnected while a recorded CSM sequence was actively running, causing the sequence to immediately stop.

• CLAAS Axion series (e.g., 850, 920, 930, 940, 950)
• CLAAS Arion series (e.g., 410, 430, 500, 600, 640)

1. 1

   Attempt to relaunch the CSM sequence to determine if the disconnect was a temporary operational glitch or a hard fault

2. 2

   Check the CLAAS vehicle CAN bus network for communication errors

3. 3

   Inspect the connectors and continuity of the harnesses linking the TR2 (A57-2) transmission module and the EXT (A62) external function module for short-circuits or open circuits

4. 4

   Check the sources of energy (fuses, power supply, and ground) for the TR2 and EXT modules

5. 5

   Check the CLAAS Sequence Management switch (S177) for signal inconsistencies or faults

1. 1

   Relaunch the Sequence

   Clear the sequence and attempt to relaunch it. Ensure the tractor meets the minimum speed requirements for CSM operation (speed must exceed 1.5 km/h for certain sequences to start).

2. 2

   Repair Wiring

   If the fault persists, repair any damaged wiring, short-circuits, or open circuits found in the CAN bus harness between the TR2 (A57-2) and EXT (A62) modules.

3. 3

   Software/Calibration Check

   Check the compatibility of the program versions, settings, and calibration of the transmission and external function modules. Update or recalibrate if required by the test and measurement files.

4. 4

   Component Replacement

   If all wiring, power sources, and software calibrations are correct but the TR2 module continues to drop the automatic gear shifting during CSM, replace the faulty component (TR2 module, EXT module, or S177 switch).