CLAAS Id78CFh / 78CFh (871) – REH (A58) - Rear lifting module: Rear lifting disconnected during a CSM sequence

Rear lifting was disconnected during a CSM (Claas Sequence Management) sequence. The rear lifting system becomes inoperative. The system is programmed to wait 20 seconds, after which the tractor initializes and attempts to relaunch the sequence automatically.

• Axion 800
• Axion 810
• Axion 850
• Axion 920
• Axion 950
• Arion 410
• Arion 430
• Arion 510
• Arion 640

1. 1

   Wait 20 seconds after the fault occurs to see if the tractor successfully initializes and relaunches the CSM sequence on its own.

2. 2

   If nothing happens after 20 seconds, manually reset the Claas Sequence Management (CSM) system.

3. 3

   Check for communication loss between the REH (A58) lifting module and the EXT (A62) external function module (this often triggers a secondary code, Id78D0h / 872).

4. 4

   Inspect the CLAAS vehicle CAN bus network, specifically the harnesses and connectors linking the REH (A58) and EXT (A62) modules, for short-circuits, open circuits, or poor pin tension.

1. 1

   Reset the System

   Perform a manual reset of the CSM via the cab controls. Clear the error codes and test the tractor to see if the anomaly returns.

2. 2

   Inspect Physical Connections

   If the fault returns, locate the REH (A58) rear lifting module and the EXT (A62) external function module. Disconnect their harnesses and inspect for corrosion, moisture, or damaged pins.

3. 3

   Test Power and Ground

   Verify the sources of energy (fuses, power supply, and ground) to both the REH (A58) and EXT (A62) modules.

4. 4

   Check CAN Bus Integrity

   Measure the resistance and continuity of the CAN bus lines between the REH (A58), EXT (A62), and the BDG (A103) network communication module.

5. 5

   Module Replacement

   If wiring, power, and grounds are all within specification and the modules still fail to communicate or execute the CSM sequence, replace the faulty module (starting with the REH A58, or the EXT A62 if CAN errors point to it) and calibrate the system.