ECU 003361.03 – DEF Dosing Injector Signal Out of Range High. John Deere System Advisory.

ECU 003361.03 (ECU 3361.03)

Code: 003361.03

Shortcode: 3361.03


This error code indicates that the DEF (Diesel Exhaust Fluid) dosing injector signal is too high, typically due to a short to 12 volts. This fault can lead to incorrect operation of the DEF injector, potentially affecting the dosing process and thus the efficiency of emissions control.


The ECU may limit or modify the DEF injection process to prevent over-dosing, which could lead to system damage or inefficient exhaust aftertreatment.


  • Inspect Wiring and Connectors: Examine the electrical connections to the DEF dosing injector for signs of damage or wear that could cause a short to voltage.
  • Measure Injector Voltage: Use a multimeter to confirm the high voltage condition at the injector’s electrical connector.
  • Rectify Electrical Faults: Repair or replace any faulty wiring or connectors to ensure proper voltage delivery to the injector.
  • Reset ECU and Test Injector Operation: After repairs, reset the ECU to clear the fault code and test the DEF dosing system under operational conditions to ensure correct function.


Maintaining proper electrical integrity in the DEF dosing system is crucial for emission control. Regular checks of the electrical system can prevent faults that compromise the DEF injection process.

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