Case IH 51 – Automated Steering System module: Operator Presence Missing

The machine's safety and automated systems require the operator to be seated to engage certain functions. This fault is triggered when the system cannot verify that the operator is in the seat, typically because the seat switch circuit is open, defective, or failing to toggle states when weight is applied.

• MX Maxxum
• Maxxum
• Puma
• Magnum
• Steiger
• MX series
• STX series
• Axial-Flow 2388
• Axial-Flow 5088
• Axial-Flow 6088
• Axial-Flow 7088
• Axial-Flow 8010

1. 1

   Software State Check: Use the Autopilot Toolbox software or the in-cab AFS diagnostic display. Navigate to the Diagnostics tab and select Operator Present Switch.

2. 2

   Physical Test: Sit down in the seat and stand back up. Verify that the switch state changes to 'Active' when you sit down and changes again when you stand up.

3. 3

   Harness Inspection: If the state does not change, inspect the 'In-Cab' leg of the wiring harness that connects to the seat switch. Look for pinched wires, continuity issues, or a disconnected plug.

4. 4

   Fuse Check: Check the cab fuse panel for a blown fuse (e.g., Fuse 10 on certain combine models) that supplies power to the seat switch circuit.

1. 1

   Prepare machine for service

   Park the machine on a level surface, turn off the engine, and disconnect the battery to ensure electrical safety.

2. 2

   Locate switch

   Locate the operator present switch, which is typically mounted under the seat cushion or integrated into the seat suspension base.

3. 3

   Disconnect harness

   Disconnect the electrical harness connector from the faulty seat switch.

4. 4

   Remove switch

   Remove the switch from the seat assembly. Depending on the specific Grammer or Sears seat model installed, this may be a twist-in style switch or secured with small screws.

5. 5

   Install new switch

   Install the new operator present switch into the seat base and secure it.

6. 6

   Reconnect harness

   Reconnect the electrical harness to the new switch.

7. 7

   Restore power

   Reconnect the battery and power on the machine.

8. 8

   Verify repair

   Return to the diagnostic display to verify that the switch state now toggles correctly when weight is applied to the seat, and clear the fault code.