BCU 523806.12 – Y75 Solenoid for PTO Speed 3 Off, Current Present at Power Module PC5. John Deere System Advisory.

BCU 523806.12 (BCU )

Code: 523806.12



Error code BCU 523806.12 is activated when the Power Module PC5 in a John Deere vehicle detects a current flow of more than 1 amp at the output for the Y75 solenoid controlling PTO Speed 3, even though the solenoid is switched off. This diagnostic trouble code indicates a potential short in the circuit or an internal fault within the power module itself, leading to unintended current flow which can cause overheating, damage to the module or solenoid, and possible electrical hazards.


The presence of current when the solenoid is supposed to be off can result in unexpected behavior of the PTO system, such as unintended activation or operational failure, which can affect the performance and safety of PTO-driven implements.


  • Inspect Wiring and Connections: Check the wiring and connections for lead 7115, focusing on signs of damage, corrosion, or loose connections that could lead to a short circuit.
  • Test for Shorts in the Circuit: Use a multimeter to test for continuity to ground when the solenoid should be off. This will help identify if there is a short causing the unexpected current.
  • Inspect the Power Module PC5: Examine the power module for any signs of damage or malfunction. A fault within the module could also lead to inappropriate power distribution.
  • Replace or Repair Faulty Components: If any damaged wires, faulty connections, or a defective power module are found, replace or repair these components to restore proper function to the PTO system.
  • Reset the Power Module and BCU: After repairs are made, reset the power module and the BCU to clear any fault codes and reinitialize the system settings.
  • Test PTO System Operation: Conduct tests to ensure the PTO Speed 3 solenoid no longer draws current when switched off and responds correctly to operational commands.
  • Regular Maintenance Checks: Incorporate regular inspections of the electrical system associated with the PTO to prevent similar issues in the future. Early detection of potential problems can save time and reduce the risk of equipment failure.


Maintaining the electrical integrity of PTO systems and their control modules is crucial for ensuring reliable operation of agricultural machinery. Regularly addressing electrical issues and ensuring all components function as expected helps prevent operational interruptions and maintains equipment safety and efficiency.