John Deere 521406.02 – AIC (Armrest Interface Control Unit): SCV XIII Control Lever Switch/Sensor Conflict

The Selective Control Valve (SCV) XIII Control Lever detent switch is in conflict with the actual physical position of the lever. The system logs this code when the signal voltage of the SCV XIII control lever is out of range, or when the switch status and the potentiometer signal voltage do not match. This typically results in limited function of that specific SCV.

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

1. 1

   Cycle Power: Turn off the tractor and cycle the key switch to attempt a system recovery and see if the code clears.

2. 2

   Inspect the Lever: Check the SCV XIII control lever for physical binding, debris, or damage that might prevent it from returning to neutral or reaching its detent positions.

3. 3

   Check Signal Voltages: Using Service ADVISOR or the tractor's diagnostic display, monitor the signal voltage of the SCV XIII control lever. Verify if the voltage is out of range or if the detent switch status fails to match the potentiometer reading.

4. 4

   Inspect Wiring: Check the wiring harness and connectors leading to the SCV Control Lever Module inside the CommandARM for loose pins, corrosion, or chafing.

1. 1

   Power down the tractor and ensure it is parked safely.

2. 2

   Access the CommandARM assembly in the cab.

3. 3

   Remove the necessary armrest trim panels to expose the internal control modules.

4. 4

   Locate the SCV Control Lever Module (specifically the bank housing SCV XIII).

5. 5

   Carefully disconnect the electrical harness connected to the SCV Control Lever Module.

6. 6

   Remove the mounting screws securing the module to the armrest chassis.

7. 7

   Remove the faulty SCV Control Lever Module and install the replacement unit.

8. 8

   Reinstall the mounting screws and reconnect the electrical harness.

9. 9

   Reassemble the CommandARM trim panels.

10. 10

    Power on the tractor and use the CommandCenter or Service ADVISOR to clear the fault codes and calibrate the new SCV lever if required.