John Deere C00 – Armrest Control Unit: Seat Switch Continuously Closed

The Armrest Control Unit has detected that the seat switch has remained in the closed (operator present) state for a continuous six-hour period. This indicates a potential short in the switch or the wiring harness. This is a critical safety issue because it prevents safety features, such as the disengagement of the header, from activating when the operator leaves the seat.

• 9560 STS
• 9650 STS
• 9660 STS
• 9760 STS
• 9860 STS

1. 1

   Have the operator get out of the seat to open the seat switch circuit. If the code clears, it may have been triggered by a long, uninterrupted period of operation.

2. 2

   Visually inspect the wiring and connections under the operator's seat for damage, corrosion, or loose connections.

3. 3

   Unplug the connector behind the seat and test switch continuity with a multimeter. The switch should be open (no continuity) when unoccupied, and closed (continuity) with weight on the seat.

4. 4

   If the switch tests correctly, inspect the wiring harness for a short circuit where the two wires may be making contact with each other or with the machine's frame.

1. 1

   Prepare machine for service

   Park the machine on a level surface, lower the header, engage the parking brake, and turn off the engine.

2. 2

   Access the switch

   Tilt the operator's seat forward to access the seat switch located on the bottom of the seat pan.

3. 3

   Disconnect switch

   Disconnect the electrical connector from the seat switch.

4. 4

   Remove old switch

   Rotate the switch assembly to release it from the seat pan or depress the tabs to pull it out.

5. 5

   Install new switch

   Insert the new switch into the seat pan, ensuring it is securely seated.

6. 6

   Reconnect

   Connect the wiring harness to the new switch.

7. 7

   Test the repair

   Turn the ignition on and verify that the fault code has cleared. Start the engine and test the operator presence system to ensure it functions correctly (e.g., with the parking brake off, the engine should stop when the operator rises from the seat).