BCU 523811.00 – Y73 Solenoid for PTO Speed 1, Current Overload Protection Active at Power Module PC5. John Deere System Advisory.

BCU 523811.00 (BCU )

Code: 523811.00



Error code BCU 523811.00 is activated when the Power Module PC5 in a John Deere vehicle measures a total amperage exceeding 40 amps at the outputs B3, C3, and D3, specifically linked to the Y73 solenoid controlling PTO Speed 1. This diagnostic trouble code suggests a serious electrical issue, such as a short to ground or a defective component within the circuits controlling the PTO speeds. The high current can lead to damage in the power module and the solenoids involved, posing a risk of further electrical system failures.


The high current condition triggers the overload protection system in the power module, which may shut down the affected outputs to prevent damage. This shutdown can lead to the non-operation of the PTO Speed 1, as well as potentially affecting PTO Speeds 2 and 3.


  • Inspect Solenoids and Associated Wiring: Check the Y73, Y75, and Y74 solenoids along with their connecting wires for signs of damage, corrosion, or wear that could contribute to a short circuit.
  • Measure Current Draw: Use a clamp meter to measure the current draw at outputs B3, C3, and D3 to identify any abnormalities and confirm the source of the overload.
  • Replace or Repair Faulty Components: If any solenoids or wires are found to be defective, replace or repair them to ensure proper operation and prevent further issues.
  • Test Power Module PC5: Ensure that the Power Module PC5 is not damaged and is functioning correctly. Replace the module if necessary to restore proper control and protection for the PTO system.
  • Reset the Power Module and BCU: After repairs are made, reset the power module and the BCU to clear the protective shutdown condition and any fault codes.
  • Test PTO System Operation: Conduct tests to ensure that the PTO system operates correctly for all speed settings without experiencing an overload condition.
  • Preventive Maintenance: Regularly schedule maintenance checks focusing on the electrical integrity of the PTO system and associated components. This helps in early detection of potential issues before they lead to system failures.


Maintaining the electrical and operational integrity of the PTO control system is essential for ensuring reliable operation of agricultural machinery. Addressing electrical faults promptly not only prevents equipment damage but also enhances the overall efficiency and productivity of the machinery. Regular electrical inspections and adherence to maintenance schedules are essential best practices for maintaining the health of critical systems like the PTO.