Deutz-Fahr 164 – ECU: Cable Break in Injector 3

The Engine Control Unit (ECU) has detected an open circuit or abnormally low current in the electrical path to the fuel injector for cylinder 3. This indicates a break or disruption in the electrical connection, which prevents proper operation of the component. When the ECU commands the injector to fire and does not detect the expected current draw, it logs this fault and may disable the injector to prevent engine damage, resulting in a rough running engine, misfiring, loss of power, and potentially white smoke from unburned fuel.

• Agrotron 110
• Agrotron 120
• Agrotron 135
• Agrotron 150
• Agrotron 175
• Agrotron 200

1. 1

   Visually inspect the engine wiring harness leading to the injectors for chafing, rubbing against engine components, heat damage, or breaks in the insulation

2. 2

   Inspect all connection points, including the main ECU connector, intermediate connectors, and the injector connector, for loose connections, backed-out pins, corrosion, or oil contamination

3. 3

   Check the pass-through connector in the rocker housing (if equipped with an internal injector harness under the valve cover) for damage or loose contacts

4. 4

   Perform a wiring harness continuity test using a multimeter between the ECU connector and the injector 3 connector, wiggling the harness to check for intermittent breaks

5. 5

   Perform an injector resistance test using a multimeter across the injector terminals (expected 0.5 to 2.0 Ohms) and compare the reading to a known working injector to check for an internal coil failure

1. 1

   Disconnect battery

   Disconnect the vehicle's battery to prevent electrical shorts.

2. 2

   Access components

   Depending on the engine, you may need to remove engine covers, the valve cover, or other components to access the injector wiring and the injector itself.

3. 3

   Repair Wiring

   If a broken wire or damaged connector is found, repair it using OEM-quality, heat-shrink butt connectors or replace the damaged section of the harness. If the damage is extensive, the entire harness may need replacement.

4. 4

   Replace Injector

   If the diagnostic tests point to a faulty injector, it must be replaced. It is often recommended to replace the entire set of injectors to ensure balanced engine performance, as mixing old and new injectors can sometimes cause issues.

5. 5

   Reassembly

   Reassemble all components in the reverse order of removal. Ensure all connectors are clean and securely fastened.

6. 6

   Clear Fault Code

   Reconnect the battery. Use a diagnostic tool to clear the fault code from the ECU's memory.

7. 7

   Verify Repair

   Start the engine and let it run for several minutes. Check if the fault code reappears. A successful repair should result in the fault code becoming inactive.