John Deere 2798.05 – Engine Control Unit (ECU): Injector High Voltage Supply #2 Circuit Has High Resistance

This code indicates that the resistance in the electrical circuit supplying the #2 fuel injector is above the normal operating range. This typically points to an open circuit, a broken wire, a loose/corroded connection, or an internal failure (open coil) within the #2 fuel injector itself.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8245R through 8400R
• 8310RT
• 8335RT
• 8360RT
• 9470RT
• 9520RT
• 9570RT
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC

1. 1

   Inspect the wiring harness leading to the #2 fuel injector for any signs of chafing, damage, wear, or disconnected/loose terminals.

2. 2

   Use a digital multimeter to measure the resistance levels within the #2 injector circuit, checking continuity from the ECU connector to the injector connector to isolate the open circuit.

3. 3

   Verify the voltage at the injection valve connector to ensure it aligns with OEM specifications and that power is reaching the injector.

4. 4

   Test the resistance across the pins of the #2 fuel injector itself to determine if the injector has failed internally (open coil).

1. 1

   Correct Electrical Faults

   If the diagnostic tests reveal a broken wire or corroded connector, repair or replace the affected section of the wiring harness or the connector pigtail.

2. 2

   Replace the Injector

   If the wiring is intact but the injector itself has an internal open circuit, safely depressurize the fuel system and replace the #2 fuel injector. (Note: When replacing an injector, it is highly recommended to replace the corresponding injector inlet connector/tube as well).

3. 3

   Reset the ECU

   After making the necessary repairs, clear the codes and reset the ECU to ensure all changes are recognized.

4. 4

   Validate Repairs

   Perform a full operational test of the fuel injection system (running the engine) to ensure it functions properly without the fault code returning.