CLAAS Id78A7h / 78A7h – EXT (A62) - External Function Module: The CSM sequence is interrupted as the driver is not sitting on the seat.

The CLAAS Sequence Management (CSM) system has been interrupted because the EXT (A62) external functions module is not receiving a valid 'driver sitting' signal from the seat occupancy sensor. This acts as a critical safety interlock to prevent the activation or continuation of automated sequences, such as lifting implements or adjusting engine speed, when the operator is not present in the driver's seat.

• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Axion 870
• Axion 920
• Axion 930
• Axion 940
• Axion 950
• Axion 960
• Arion 400 series
• Arion 500 series
• Arion 600 series

1. 1

   Verify that the operator is not accidentally lifting their weight off the seat (e.g., turning around to look at an implement) while a CSM sequence is active.

2. 2

   Locate the operator presence switch (seat contact switch) under the seat cushion. Use a multimeter to test for proper continuity when weight is applied to the seat and an open circuit when weight is removed.

3. 3

   Inspect the wiring harness and connectors running from the seat switch to the EXT (A62) module. Look for pinched wires, chafing under the seat suspension mechanism, or loose connector pins.

1. 1

   Turn off the tractor ignition and disconnect the battery ground

   to prevent short circuits.

2. 2

   Slide the seat forward/backward

   as needed to access the wiring harness underneath.

3. 3

   Disconnect the electrical connector

   for the operator presence switch.

4. 4

   Remove the seat cushion

   Depending on the seat manufacturer (Grammer or Sears), remove the seat cushion. This usually involves releasing retaining clips or removing mounting screws at the base of the cushion.

5. 5

   Remove the faulty seat contact switch

   from the cushion assembly.

6. 6

   Install the new operator presence switch

   and route the wiring safely away from the seat's mechanical suspension pinch points.

7. 7

   Reinstall the seat cushion and reconnect the electrical harness

8. 8

   Verify the repair

   Reconnect the battery, turn on the ignition, sit in the seat, and initiate a CSM sequence to verify the repair and ensure the code does not return.