Massey Ferguson 656.05 – ECU (Engine Control Unit): Injector Number 6 Low Amp Draw

The Engine Control Unit (ECU) is detecting that the electrical current (amperage) flowing through the fuel injector on cylinder number 6 is lower than expected, or the circuit has abnormally high resistance. This typically points to an open circuit, a damaged wiring harness, a loose connector, or a failed internal solenoid within the injector itself.

• 4710
• 7724S
• Interim Tier 4 (2012-2015)
• 7722S
• 7722
• 7615
• 7720S
• 7716
• 7718
• 7726
• 7715
• 7616
• 7618
• 4708
• 7619
• 7626
• 7726S
• 7624
• 4707
• 4709
• 7614
• 7718S
• 7620
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 7622
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 8650
• 8690
• 8727
• 8737

1. 1

   Visual Inspection: Inspect the wiring harness leading to the #6 fuel injector. Look for chafed wires, melted insulation, or signs of rodent damage.

2. 2

   Connector Check: Disconnect the electrical plug at the #6 injector. Check for corrosion, bent pins, or moisture inside the connector. Reconnect it to ensure it is seated properly.

3. 3

   Resistance Test (Ohm Test): Using a multimeter, measure the resistance across the two pins of the #6 injector. Compare this reading to a known good injector on the same engine (e.g., Injector #5). If the resistance is significantly higher or shows an open circuit (infinite ohms), the injector solenoid has failed internally.

4. 4

   Harness Continuity Test: Disconnect the harness from the ECU and the injector. Test the continuity of the wires between the ECU pins and the injector connector to rule out a broken wire in the harness.

1. 1

   Preparation

   Disconnect the tractor's battery to prevent electrical shorts. Clean the area around the #6 injector thoroughly to prevent dirt from entering the engine or fuel system.

2. 2

   Remove Fuel Lines

   Carefully loosen and remove the high-pressure fuel line connecting the common rail to the #6 injector. Cap the rail and line to prevent contamination. Remove the fuel return (leak-off) line.

3. 3

   Disconnect Wiring

   Unplug the electrical connector from the injector.

4. 4

   Remove the Injector

   Remove the injector hold-down clamp or retaining bolt. Carefully extract the injector from the cylinder head. (A slide hammer or specialized injector puller may be required if it is stuck).

5. 5

   Clean the Bore

   Clean the injector bore in the cylinder head, ensuring the old copper sealing washer is removed and the seating surface is spotless.

6. 6

   Install New Injector

   Fit a new copper sealing washer and O-ring to the new injector. Slide the injector into the bore and torque the hold-down clamp to the manufacturer's specified torque.

7. 7

   Reassemble

   Reconnect the high-pressure fuel line (do not over-tighten) and the fuel return line. Plug in the electrical connector.

8. 8

   Bleed the System & Calibrate

   Reconnect the battery. Prime the fuel system to remove air. Note: Common rail injectors often require the new injector's calibration code (IQA code) to be programmed into the ECU using a diagnostic tool so the engine runs smoothly.

9. 9

   Test

   Start the engine, check for fuel leaks, and verify that the fault code has cleared.