AIC 521136.31 – CommandQuad™ Range Switches Conflict. John Deere AIC System Alert.

AIC 521136.31 (AIC )

Code: 521136.31



This error code, AIC 521136.31, occurs when a fault with the CommandQuad™ transmission’s range switch A causes it and possibly other switches to be erroneously read as pressed simultaneously. This situation can create conflicting signals within the transmission system, leading to incorrect gear selections and potential operational hazards.


The control unit has initiated a safety protocol by placing the vehicle in a recoverable PARK position to prevent unintended movements and ensure safety until the issue is resolved.


  • Inspect range switch A and any other affected switches for mechanical issues that might cause them to stick or fail to return to the neutral position. Check for debris, damage, or wear that could impact the switch operation.
  • Test each switch individually using diagnostic tools to confirm their proper functioning. Ensure that each switch independently registers its pressed and unpressed states accurately.
  • Examine the electrical connections for each implicated switch, looking for shorts, disconnections, or other wiring issues that could cause erroneous readings.
  • Replace any faulty switches or repair any identified electrical issues. Ensure that all new or repaired components are correctly installed and fully integrated into the system.
  • After completing repairs, recalibrate the affected transmission settings and thoroughly test the system to ensure all conflicts are resolved and that the vehicle can safely exit the PARK position.


Regular checks and timely maintenance of transmission range switches are crucial for the safe and efficient operation of machinery equipped with CommandQuad™ systems. Addressing conflicts promptly helps maintain operational reliability and prevents more severe mechanical or safety issues.