John Deere 3361.03 – Engine Control Unit (ECU): DEF Dosing Injector Signal Out of Range High

The Engine Control Unit (ECU) has detected an abnormally high voltage in the electrical circuit of the Diesel Exhaust Fluid (DEF) dosing injector. This condition suggests a short circuit to a power source within the injector's wiring or the injector itself, preventing the aftertreatment system from accurately controlling the injection of DEF 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
• 9R
• 9RT
• 9RX
• 9470RT
• 9520RT
• 9570RT
• 6R
• 7R
• 8R
• 744K
• 750K
• 824K
• 844K
• 850K
• 1050K
• S7
• X9
• CH570
• CH670

1. 1

   Inspect the wiring harness between the ECU and the DEF dosing valve for a short to a 12V power source or an open circuit

2. 2

   Disconnect the DEF injector and inspect the electrical connector for corrosion, bent pins, or moisture

3. 3

   Verify the supply voltage at the connector and check the ground return continuity from the sensor back to the ECU ground

4. 4

   Test the DEF injector coil for an internal short circuit

5. 5

   Visually inspect the base of the DEF dosing valve and the ring seal surface for signs of heavy corrosion, pitting, or crystallized DEF leaks, which can cause the injector to short out internally

1. 1

   Power Down

   Turn off the machine and disconnect the battery to ensure electrical safety.

2. 2

   Access the Injector

   Locate the DEF dosing injector, which is mounted on the exhaust aftertreatment system (SCR catalyst).

3. 3

   Perform Wiring Repairs

   If the diagnostic checks revealed a short to 12V in the harness, repair or replace the damaged section of the wiring harness.

4. 4

   Remove the DEF Injector

   If the wiring is intact and the injector coil is internally shorted, disconnect the electrical connector and the DEF fluid lines. Remove the mounting hardware securing the valve.

5. 5

   Clean the Port

   Inspect the mounting port on the exhaust for crystallized DEF or carbon buildup. Clean the surface thoroughly to ensure a proper seal.

6. 6

   Install the New Injector

   Install the replacement DEF dosing injector using a brand-new gasket.

7. 7

   Reconnect

   Reattach the DEF fluid lines and plug in the electrical connector. Reconnect the battery.

8. 8

   Software Reset

   Clear the fault codes using a diagnostic tool. Note: Depending on the machine, clearing an active SCR inducement/derate after a DEF injector failure may require a pump pressure, flow, and emissions test initiated via John Deere Service ADVISOR software.