BRC 000168.04 – Low Unswitched Supply Voltage in Brake Control Unit. John Deere System Advisory.

BRC 000168.04 (BRC 168.04)

Code: 000168.04

Shortcode: 168.04


The error code BRC 000168.04 indicates a low unswitched supply voltage in the Brake Control Unit (BRC), where the voltage has fallen below the critical threshold of 9.0 volts. This condition refers to the constant power supply to the BRC, which is crucial for retaining settings and operating certain features even when the vehicle is turned off.


Upon detection of low unswitched supply voltage, the system triggers an indicator or alarm to alert the operator. This serves as a warning that the voltage necessary for some functions might be insufficient, although it does not immediately affect the operation of the brake system.


  • Inspect Battery and Connections: Check the battery, especially if it provides the unswitched voltage supply, for adequate charge and health. Ensure all connections are tight and free of corrosion.
  • Test Voltage Supply: Measure the unswitched supply voltage to the BRC using a multimeter to confirm if it is indeed below 9.0 volts.
  • Examine Wiring and Connectors: Look for any signs of wear, damage, or loose connections in the wiring and connectors that could be causing the voltage drop.
  • Rectify Electrical Faults: Repair or replace any defective electrical components that are contributing to the low voltage issue.
  • Verify System Functionality Post-Repair: After addressing the voltage issues, test the system to ensure that the unswitched supply voltage remains stable and above 9.0 volts.


Regular monitoring and maintenance of the electrical supply to the Brake Control Unit are critical to avoid potential operational disruptions. Early detection and correction of voltage issues can help maintain the effectiveness of the brake control system and prevent further electrical problems.