ACU 523967.02 – Speed Band 2 Switch and Voltage Mismatch

ACU 523967.02 (ACU )

Code: 523967.02



Error code ACU 523967.02 indicates a conflict between the position of the Speed Band 2 switch and the corresponding analog voltage readings. This mismatch can be indicative of issues in the switch mechanism or problems in the electrical circuitry affecting accurate voltage measurement.


Due to this detected inconsistency, the control unit has limited the functionality of certain features to prevent potential operational errors that could arise from incorrect speed band settings.


  • Inspect the Speed Band 2 switch for physical defects or operational issues that might impair its ability to correctly modify or represent voltage changes.
  • Measure the actual voltage output when the Speed Band 2 switch is engaged, using a multimeter to ensure the readings correspond accurately with the switch position.
  • Check all related wiring and connections for any signs of wear, damage, or looseness that could be influencing the voltage discrepancies.
  • If the switch and wiring are intact but the issue persists, recalibrate or adjust the switch settings to align with expected voltage outputs.
  • Consider replacing the Speed Band 2 switch if recalibration does not correct the voltage mismatch, especially if there is evidence of mechanical failure or if the switch is outdated.


It’s crucial for the switch positions and their corresponding voltage levels to be synchronized accurately to maintain proper control and functionality of the machinery. Regular maintenance and prompt corrective actions upon detecting mismatches are essential to ensure reliable operation and safety.