John Deere 655.06 – Engine Control Unit (ECU): Injector Number 5 Circuit Has Low Resistance

The Engine Control Unit (ECU) has detected a low resistance condition in the electrical circuit for the number 5 fuel injector. This indicates that the electrical resistance is below the manufacturer's specified range, which suggests a potential short circuit to ground in the injector's wiring harness or an internal short within the injector's solenoid coil itself.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5065M
• 5075M
• 7720
• 7820
• 7920
• 7810
• 7185J
• 7195J
• 7205J
• 7210J
• 7225J
• 9200
• 9300
• 9400
• 444J
• 544J
• 624J
• 750J
• 850J
• 4930

1. 1

   Visually inspect the 60-way ECU connector and the specific injector connector for dirty, damaged, contaminated, or poorly positioned terminals.

2. 2

   Check the wiring harness between the ECU and the #5 injector for chafing, melting, or short circuits to ground or power.

3. 3

   Measure the resistance of the cylinder #5 injector solenoid to determine if the injector itself is internally shorted.

4. 4

   OEM Tool Warning: You must use the JT07328 Connector Adapter Test Kit when making measurements on connector terminals. Do not force standard multimeter probes or paperclips directly into the terminals, as this will cause terminal damage.

1. 1

   Safety First

   Disconnect battery power before servicing the engine's electrical system. If the repair requires removing the injector, relieve the fuel system pressure (High-Pressure Common Rail systems hold dangerous pressure).

2. 2

   Harness Repair

   If the diagnostic tests reveal a short in the wiring, repair the damaged section of the harness or replace the injector wiring harness entirely.

3. 3

   Injector Replacement

   If the wiring tests good but the injector solenoid has low resistance, the Electronic Unit Injector (EUI) has failed internally. Remove the valve cover (if applicable to your specific engine model) and replace the Cylinder #5 injector.

4. 4

   Calibration

   On certain engines (like the 9.0L), program the new QR code / calibration file into the ECU so the controller recognizes the new part's flow rate.

5. 5

   Reassembly & Verification

   Reassemble all components, reconnect the battery, and clear the ECU codes. Restart the engine to verify that the 000655.06 code does not return and the engine runs smoothly.