ACU 523961.07 – Park Lock Engagement Discrepancy

ACU 523961.07 (ACU )

Code: 523961.07



This error code, ACU 523961.07, indicates a mismatch between the actual and desired states of the park lock mechanism. This condition can arise when the park lock fails to engage or disengage as commanded, possibly due to mechanical or electronic control issues.


To prevent accidental movement and ensure safety, the control unit automatically defaults the transmission to neutral when this discrepancy is detected.


  • Inspect the park lock mechanism for any signs of wear, damage, or obstruction that could prevent it from operating correctly. Ensure that all moving parts are lubricated and free of debris.
  • Test the electronic controls and sensors associated with the park lock mechanism to ensure they are accurately relaying the correct commands and status information.
  • Check the wiring and connections for any signs of damage or corrosion that could affect signal transmission between the control unit and the park lock mechanism.
  • Perform a diagnostic scan to identify any related error codes or system malfunctions that could be influencing the park lock’s behavior.
  • If issues persist after these checks, recalibrate or reset the park lock system settings according to the manufacturer’s instructions.
  • In cases where mechanical or electronic adjustments do not resolve the fault, it may be necessary to replace the park lock mechanism or related components.


Ensuring that the park lock mechanism functions correctly is critical for vehicle safety. Regular checks and maintenance are recommended to prevent such faults and ensure that the vehicle operates safely and as intended.