John Deere 651.05 – ECU: Injector 1 High Resistance Error

The Engine Control Unit (ECU) has detected an open circuit or abnormally high electrical resistance in the electronic fuel injector circuit for cylinder number 1. Because the circuit is compromised, the injector may fail to deliver fuel to the cylinder, and the controller will typically disable the injector to prevent engine damage.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 9470RT
• 9520RT
• 9570RT
• 444J
• 544J
• 624J
• 750J
• 850J
• 444K

1. 1

   Visually check the wiring harness and connectors leading to the cylinder 1 injector for signs of physical damage, chafing, corrosion, or loose connections.

2. 2

   Measure the resistance in the cylinder 1 injector circuit using a multimeter to confirm the open circuit or high resistance condition.

3. 3

   Verify the high voltage supply from the ECU to the injector, as an open circuit in the shared supply line can cause this code.

4. 4

   Test the resistance across the injector solenoid terminals directly to determine if the high resistance is internal to the injector or isolated to the wiring harness.

1. 1

   Address Wiring Issues

   If diagnostic checks reveal damaged wires or corroded connectors, repair or replace the affected section of the wiring harness or connector pigtail to restore proper circuit continuity.

2. 2

   Replace the Injector

   If the wiring and ECU voltage supply test perfectly fine but the injector itself has an internal open circuit or high resistance, remove and replace the cylinder 1 electronic fuel injector.

3. 3

   Program the Trim Code

   When installing a new common rail injector, ensure the new injector's calibration or trim code (QR code) is programmed into the ECU.

4. 4

   Clear Codes and Test

   Reset the ECU to clear the fault codes. Run the engine and perform system tests to confirm that the injector circuit is functioning correctly and the 000651.05 code does not return.