John Deere 3361.31 – ECU: DEF Dosing Injector Active Without Injection

The Engine Control Unit (ECU) commanded the Diesel Exhaust Fluid (DEF) dosing injector to open, but it did not detect the expected corresponding drop in DEF pressure. This indicates that the injector is mechanically stuck closed, clogged, or failing to actuate, meaning no DEF is actually being injected into the exhaust stream.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 250GLC
• 300GLC
• 350GLC
• 380GLC
• 624K
• 644K
• 724K
• 744K
• 824K
• 844K
• 750K
• 850K
• 1050K
• 670G
• 672G
• 5M Series
• 5085M
• 5095M
• 6105M
• 8R Series
• 8RW Series
• 9R
• 9RT
• 9470RT
• 9520RT
• 9570RT
• 9RX Series
• S7 Series
• X9 Series

1. 1

   Examine the DEF dosing injector and surrounding lines for physical obstructions, severe mechanical wear, or external leaks.

2. 2

   Use a diagnostic tool (like John Deere Service ADVISOR) to manually command the injector to open and verify if the actuator responds to control signals.

3. 3

   Remove the injector from the exhaust pipe (leaving the fluid and electrical lines connected) and perform a pressure test to check the spray pattern. If the injector does not fire properly or the spray pattern is distorted/absent, the injector has failed.

1. 1

   Remove the Dosing Injector

   Disconnect the electrical harness and DEF supply line from the DEF dosing injector. Unbolt and remove the injector from the exhaust aftertreatment assembly.

2. 2

   Bench/Spray Test

   Perform the spray pattern test mentioned in the diagnostics phase to definitively condemn the part.

3. 3

   Install New Injector

   If the injector is not firing properly, install a new DEF dosing injector. Torque mounting bolts to OEM specifications and reconnect the DEF fluid line and electrical connector.

4. 4

   Force a Regeneration

   Put the machine into a forced stationary regeneration (regen) cycle using your diagnostic tool.

5. 5

   Monitor the Regen

   Allow the unit to run through the complete regen cycle (this can take up to 3 hours depending on soot/DEF load) to ensure the SCR system is dosing correctly and temperatures are nominal.

6. 6

   Clear Codes and Test

   Once the regen is complete, clear the 003361.31 fault code from the ECU. Run and test the machine under load to verify the code does not return.