ECU 522994.04 – ECU Power Supply Output #2 Circuit Has Low Resistance. John Deere System Advisory.

ECU 522994.04 (ECU )

Code: 522994.04



This diagnostic trouble code indicates that the ECU detected low resistance in the power supply output 2 circuit, which is lower than the sensor low voltage specification. Low resistance in this circuit typically suggests a short to ground, which can affect the proper functioning of the ECU and connected components.


The affected power supply circuit may experience issues, potentially leading to reduced performance or malfunction of connected sensors and components.


  • Inspect ECU Power Supply Wiring and Connections: Check for damaged, frayed, or loose wiring and connectors associated with the ECU power supply output 2 circuit. Repair or replace as necessary.
  • Test ECU-J1 and ECU-J2 Connectors: Use diagnostic tools to test the ECU-J1 and ECU-J2 connectors for proper connection and functionality. Ensure that there are no issues with these connectors.
  • Check for Short Circuits: Inspect the circuit for any points where wires may be touching ground, causing a short circuit. Repair or insulate as needed.
  • Reprogram Control Units: If necessary, reprogram the control units to ensure proper functionality and synchronization.
  • Reset ECU and Monitor System: After resolving the issue, reset the ECU to clear the fault code and monitor the system to ensure normal operation.


Maintaining proper electrical connections and resistance in the ECU power supply circuits is crucial for accurate sensor and component operation. Regular inspections and timely maintenance can help prevent electrical-related issues.

Control Units: John Deere

John Deere Parts
John Deere Logo