CLAAS Id78CAh / 78CAh – EXT (A62): No CSM sequence can be read or recorded. The driver is not sitting on the seat.

The system aborts or prevents the recording/playback of headland management sequences because the operator presence switch does not detect a driver in the seat.

• CLAAS Axion 800 series (810, 850)
• CLAAS Axion 900 series (920, 950)
• CLAAS Arion 500 and 600 series (510, 640)

1. 1

   Verify that the operator is fully seated with their weight on the seat cushion when attempting to read or record a CSM sequence

2. 2

   Test the operator presence switch (seat switch) for proper continuity when weight is applied

3. 3

   Inspect the wiring harness and connectors running from the seat switch to the EXT (A62) module for breaks, chafing, or loose connections

1. 1

   Clear the Code Operationally

   Sit in the seat and attempt to run the CSM sequence again. If the code clears, it was simply an operational error.

2. 2

   Access the Switch

   If the code remains active, turn off the tractor ignition. Lift or remove the seat cushion to access the operator presence switch (usually located within the Grammer seat suspension base).

3. 3

   Test the Circuit

   Disconnect the seat switch and use a multimeter to test for continuity. The switch should close the circuit when weight is applied and open it when weight is removed.

4. 4

   Replace the Switch

   If the switch fails the continuity test or is physically damaged, remove the faulty switch and install a replacement.

5. 5

   Reassemble and Test

   Reconnect the wiring harness, reinstall the seat cushion, turn on the ignition, and verify that the CSM sequence can now be recorded/read without triggering Id78CAh.