CLAAS Id78B3h / 78B3h (843) – TR2 (A57-2) Transmission Module: Field end maneuvering gear disconnected during a sequence CSM

This fault occurs when the transmission module detects a communication loss or disconnection regarding the field end maneuvering gear while a Claas Sequence Management (CSM) sequence is actively running. The active CSM sequence is immediately stopped.

• CLAAS Axion 800 Series (810, 820, 850)
• CLAAS Axion 900 Series (920, 950)
• CLAAS Arion 600/500 Series (510, 640)
• CLAAS Arion 400 Series (410, 430)

1. 1

   Check the TR2 Transmission Module (A57-2): Verify power, ground, and CAN bus communication.

2. 2

   Check the EXT External Function Module (A62): Ensure it is communicating properly with the TR2 module.

3. 3

   Check the 'Claas Sequence Management' Switch (S177): Verify the switch is functioning and sending the correct signals.

4. 4

   Check the HYD Hydraulic Module (A60): Ensure there are no communication drops on the hydraulic side of the CSM sequence.

5. 5

   Harnesses and Connectors: Check the connectors and continuity of the wiring harnesses linking the TR2, EXT, and HYD modules. Look specifically for short-circuits or open circuits.

6. 6

   Power Sources: Check the sources of energy (fuses, supply voltage, and ground) for the transmission and external function modules.

1. 1

   Replicate and Clear

   Attempt to relaunch the CSM sequence to see if the fault is a hard fault or intermittent. If it immediately returns, proceed to electrical testing.

2. 2

   Inspect Wiring

   Visually inspect the wiring harnesses connecting the TR2 (A57-2) module to the EXT (A62) module. Clean the connector pins with contact cleaner and ensure they are seated tightly.

3. 3

   Test the CSM Switch

   Use a multimeter to test the S177 Claas Sequence Management switch on the console. Ensure it shows proper continuity when engaged and doesn't have internal resistance issues.

4. 4

   Test CAN Bus Communication

   Check the Powertrain CAN bus and CLAAS vehicle CAN bus networks for proper voltage (typically ~2.5V on CAN High and CAN Low) to ensure the TR2 and EXT modules are successfully passing data.

5. 5

   Module Replacement/Reprogramming

   If the wiring, fuses, and switches test good, the fault lies within the TR2 (A57-2) or EXT (A62) module. The module will need to be replaced and calibrated/reprogrammed using the CLAAS Diagnostic System (CDS).