ACU 523923.04 – Low Voltage in SCV I Control Lever Sensor

ACU 523923.04 (ACU 523923.04)

Code: 523923.04

Shortcode: 523923.04


This error code, ACU 523923.04, is triggered when the voltage at the SCV I (Selective Control Valve I) control lever sensor falls below 0.2 volts. Such a low voltage is indicative of potential electrical issues, such as insufficient power supply, disconnections, or a failing sensor.


Due to this low voltage reading, the SCC (System Control Computer) has automatically disabled SCV I to prevent malfunctioning of the hydraulic operations and ensure safety.


  • Check the electrical connections and wiring to the SCV I control lever sensor for loose connections, breaks, or corrosion that might be causing voltage drops.
  • Use a multimeter to verify the voltage output at the sensor. Ensure that it aligns with operational standards specified in the technical manual.
  • Investigate the power source and wiring integrity that feeds into the sensor to identify any potential points of failure.
  • Replace the sensor if it is determined to be faulty or if connections and wiring appear intact and functional.
  • After resolving the underlying electrical issues, recalibrate or reset the sensor settings to ensure it operates correctly within the control system.


Maintaining proper voltage levels at control sensors is crucial for the accurate functioning of hydraulic systems in heavy machinery. Regular inspections and timely maintenance of electrical components can prevent such voltage-related issues and ensure operational reliability.