ECU 005435.14 – DEF Dosing Unit Pump Motor Fault. John Deere System Advisory.

ECU 005435.14 (ECU 5435.14)

Code: 005435.14

Shortcode: 5435.14


This diagnostic trouble code indicates that the DEF dosing unit pump motor is sending an incorrect signal. This condition can affect the proper functioning of the DEF dosing system.


The ECU may limit or adjust the operation of the DEF dosing system to manage the incorrect signal and ensure safe operation of the emissions control system.


  • Inspect DEF Pump Motor Wiring and Connections: Check for damaged, frayed, or loose wiring and connectors associated with the DEF dosing unit pump motor. Repair or replace as necessary.
  • Test DEF Pump Motor: Use diagnostic tools to test the DEF dosing unit pump motor for proper operation and signal integrity. Replace the pump motor if it is faulty.
  • Verify Motor Signals: Ensure that the signals sent by the DEF dosing unit pump motor are accurate and within specifications.
  • Check for Electrical Interference: Inspect the system for any sources of electrical interference that might affect the pump motor signals.
  • 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 operation and signal integrity of the DEF dosing unit pump motor is crucial for accurate DEF dosing and emissions control. Regular inspections and timely maintenance can help prevent signal-related issues.

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