BCU 002386.05 – E27 Beacon Light On, No Current Detected at Power Module PC6. John Deere System Advisory.

BCU 002386.05 (BCU 2386.05)

Code: 002386.05

Shortcode: 2386.05


Error code BCU 002386.05 is activated when the Power Module (High Frequency) PC6 in a John Deere vehicle detects a current of less than 500 mA on lead 1004 for the E27 beacon light, despite the light being switched on. This significantly low current suggests an open circuit condition, likely caused by a disconnected wire, a faulty beacon light, or a break in the connection within the beacon light circuit.


The system may respond by attempting to activate the beacon light but will fail to do so effectively due to the lack of sufficient current. This may lead to a malfunction in visibility or signaling, compromising safety features. The BCU may alert the operator via dashboard indicators, signaling a malfunction in the beacon light operation.


  • Inspect Beacon Light Circuit: Carefully examine the beacon light and its associated wiring for any signs of disconnection, damage, or wear that could result in an open circuit.
  • Check Connections and Continuity: Ensure that all connectors and wiring specifically leading to and from the beacon light are secure and intact. Use a multimeter to test the continuity of the beacon light circuit from the power module to the light itself.
  • Repair or Replace Faulty Components: If a disconnection or break in the circuit is identified, repair the wiring or replace the faulty components to restore proper function.
  • Test Beacon Light Functionality: After repairs are made, test the beacon light to ensure it draws the correct current and functions as expected when activated.
  • Reset the Power Module and Clear Diagnostic Codes: Reset the power module PC6 to clear any diagnostic trouble codes and retest the system to ensure the beacon light operates without further issues.
  • Monitor System Operation: Continue to monitor the beacon light to ensure no further issues of low current or open circuit arise, confirming the effectiveness of the repairs.


Regular maintenance and timely inspections of vehicle lighting systems are critical to ensure they function efficiently and reliably. Addressing issues like open circuits in beacon lights promptly can prevent larger system failures and ensure continuous operational safety. This proactive approach helps maintain the integrity and safety of the vehicle’s signaling and visibility functions.