CCU 523916.03 – Hydraulic Oil Filter Restriction Sensor Circuit Voltage High

CCU 523916.03 (CCU )

Code: 523916.03



This fault code indicates that the voltage in the hydraulic oil filter restriction sensor circuit is higher than normal, which can suggest a short to a high voltage source or a fault in the sensor itself. This high voltage condition might lead the system to incorrectly assume that the filter is not restricted.


The control unit assumes that the filter is not restricted. If the last known state of the filter was restricted, the system commands a slow idle until the operator shuts off the engine to prevent damage.


  • Inspect Sensor and Wiring: Check the hydraulic oil filter restriction sensor and its wiring for signs of damage, corrosion, or short circuits. Repair or replace any faulty components.
  • Test Voltage Levels: Use a multimeter to measure the voltage at the sensor to confirm if it is indeed high. Compare readings with the specified normal range.
  • Replace Faulty Sensor: If the sensor is found to be defective, replace it to ensure accurate pressure readings.
  • Check System Calibration: Verify that the sensor and associated systems are properly calibrated to avoid false readings.
  • Monitor System After Repairs: After addressing the issue, reset the system and monitor it to ensure that normal operation is restored and the fault code does not recur.


Ensuring the integrity of the hydraulic oil filter restriction sensor and its circuitry is essential for accurate monitoring and maintenance of the hydraulic system. Regular inspections and prompt repairs of electrical components can help maintain system performance.

Control Units: John Deere

John Deere Parts
John Deere Logo