BCU 523692.12 – Current Detected When Upper Worklights on Cab Frame Are Off. John Deere System Advisory.

BCU 523692.12 (BCU )

Code: 523692.12



Diagnostic trouble code BCU 523692.12 is activated when the power module PC0 measures a current exceeding 1 amp in lead 1029, which is designated for the upper worklights on the cab frame, even though these lights are switched off. This condition generally indicates a short in the circuit or an internal fault within the power module itself, which can lead to unexpected power consumption and potential damage to the electrical system.


The power module likely initiates a protective shutdown of the affected circuit to prevent further damage or hazards, such as overheating or electrical fires, while maintaining this fault state to alert the operator.


  • Inspect Circuit for Damage: Thoroughly examine the wiring and components connected to lead 1029. Look for signs of damage, such as exposed wires, worn insulation, or any abnormalities that might cause a short circuit.
  • Test for Short to Ground: Use a multimeter to test the circuit for continuity and check for a short to ground. Focus on identifying the specific locations where shorting may occur.
  • Replace Faulty Wiring or Components: If any specific areas of damage or malfunction are identified, replace the faulty wiring or components to resolve the short circuit issue.
  • Ensure Proper Load and Connections: Verify that the load specifications and connections within the circuit are correct and meet the manufacturer’s standards to avoid overloading and future shorts.
  • Reset and Test the System: After repairs, reset the power module and test the system operation to ensure no current flows when the worklights are off and that the issue is fully resolved.


Regular maintenance and proactive checks of the vehicle’s electrical systems are essential to identify and rectify such issues promptly. Ensuring that all systems function correctly without unwanted current flow when devices are off is crucial for safety and efficiency.