John Deere 521408.02 – AIC / HCC: Rear Hitch Return to Lower Set Point Switch Conflict

The system detects an error when reading the LIN Bus signal for the button used to select the saved operating depth. The controller registers a conflict, which often means the 'Rear hitch lower setpoint button' located on the armrest hitch controls module is either sending an erratic signal, has lost communication on the LIN Bus, or is physically stuck in the pressed condition for too long.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R
• 9470RT
• 9520RT
• 9570RT

1. 1

   Inspect the rear hitch lower setpoint button on the armrest hitch controls module to see if it is physically stuck, jammed by debris, or collapsed.

2. 2

   Move the quick raise/lower switch to the center position to see if the system recovers and clears the conflict.

3. 3

   Inspect the wiring harness and connectors between the Armrest Hitch Controls Module and the AIC/HCC for pinched wires, corrosion, or loose pins.

4. 4

   Use John Deere Service ADVISOR to monitor live LIN Bus data for the armrest module to verify the button state.

1. 1

   Attempt Reset

   Move the quick raise/lower switch to the center position. Cycle the tractor's key power to see if the code goes from Active to Stored.

2. 2

   Clean the Module

   If the button is sticking, carefully clean the perimeter of the saved depth button on the armrest with electrical contact cleaner or compressed air to dislodge any farming debris or spilled liquids.

3. 3

   Repair Wiring

   If diagnostic checks revealed a drop in LIN Bus voltage or a damaged harness leading to the armrest, repair the wiring fault and secure the harness.

4. 4

   Replace the Module

   If the wiring is intact and the button is internally shorted or the LIN Bus transmitter inside the switch has failed, the switch assembly cannot be repaired. You must replace the Armrest Hitch Controls Module.

5. 5

   Clear and Test

   After replacing the module, clear the AIC/HCC fault codes. Start the tractor and test the rear hitch return-to-lower function to verify the repair.