Massey Ferguson 3361.07 – Engine ECU (EEM4): DEF Injector Has Not Opened Or Closed As Expected

DEF dosing valve is blocked or does not reach the physical position commanded by the control unit.

• 4710
• 7724S
• 5712SL
• 7722S
• 7722
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 4708
• 7726S
• 4707
• 4709
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• MF 4707
• MF 4708
• MF 4709
• MF 4710
• MF 5608
• MF 5609
• MF 5610
• MF 5611
• MF 5612
• MF 5613
• MF 5710 SL
• MF 5711 SL
• MF 5712 SL
• MF 5713 SL
• MF 7614
• MF 7615
• MF 7616
• MF 7618
• MF 7619
• MF 7620
• MF 7622
• MF 7624
• MF 7626
• MF 7714
• MF 7715
• MF 7716
• MF 7718
• MF 7719
• MF 7720
• MF 7722
• MF 7724
• MF 7726
• MF 7714 S
• MF 7715 S
• MF 7716 S
• MF 7718 S
• MF 7719 S
• MF 7720 S
• MF 7722 S
• MF 7724 S
• MF 7726 S

1. 1

   Inspect the injector tip and the exhaust mixer area for urea crystal buildup that could be physically blocking the injector nozzle

2. 2

   Ensure the DEF fluid is ISO-compliant and free of dirt or debris, which can damage the injector nozzle and restrict flow

3. 3

   Inspect the wiring harness and connector at the DEF dosing valve for signs of a short circuit or open load

4. 4

   Run a DEF Dosing Valve Test, DEF Quantity Test, and DEF System Leak Test using a diagnostic tool to verify if the injector is mechanically stuck or if the issue lies in the DEF pump pressure

1. 1

   Preparation

   Ensure the engine and exhaust system are completely cool to avoid burns. Disconnect the tractor's battery to prevent electrical hazards.

2. 2

   Locate the Injector

   Find the DEF injector (dosing valve). On newer models like the 5700 SL series, it is mounted directly to the compact 'All-In-One' SCR exhaust treatment system located under the cab/hood.

3. 3

   Disconnect Lines

   Press the release tab to disconnect the electrical connector from the injector. Disconnect the DEF fluid line, keeping a clean container nearby to catch any residual fluid.

4. 4

   Remove the Injector

   Use a socket wrench to remove the mounting bolts securing the injector assembly to the exhaust manifold/mixer. Gently pull the injector out (a removal tool may be necessary if it is seized by crystallized DEF).

5. 5

   Clean the Port

   Thoroughly clean the mounting port and surrounding area with a clean rag to remove any debris or urea deposits.

6. 6

   Install the New Injector

   Insert the new DEF injector into the port, ensuring it seats properly. Reattach the mounting bolts and tighten them to the manufacturer's torque specifications.

7. 7

   Reconnect and Test

   Reconnect the DEF fluid line and the electrical connector (ensure it clicks into place). Reconnect the battery. Turn the machine on and use a diagnostic tool to clear the fault codes and run a DEF system test to verify optimal performance.