DSM 000168.04 – Control Unit Supply Voltage Too Low. John Deere System Advisory.

DSM 000168.04 (DSM 168.04)

Code: 000168.04

Shortcode: 168.04


This diagnostic trouble code (DSM 000168.04) is triggered when the control unit detects a supply voltage below 9 volts. Low supply voltage can be caused by a failing battery, poor connections, or issues with the charging system.


A supply voltage below 9 volts can lead to insufficient power for the control unit, potentially causing malfunctions or shutdowns of critical systems. This is a protective measure to prevent erratic behavior or damage due to low voltage.


  • Inspect Battery and Charging System: Check the condition of the battery and the performance of the charging system, including the alternator.
  • Examine Connections: Ensure all electrical connections are secure, clean, and free of corrosion. Loose or corroded connections can lead to voltage drops.
  • Test for Voltage Drops: Use diagnostic tools to measure voltage levels across the electrical system and identify points where voltage drops occur.
  • Update Control Software: Ensure the control unit software is current and properly configured, as updates may improve voltage management.
  • Replace Faulty Components: Replace any damaged or failing components in the electrical system that may be causing the low voltage condition.


Maintaining a healthy electrical system with regular checks can prevent low voltage conditions and ensure reliable operation of the control unit and associated systems.

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