Iveco 164 – Engine Control Unit (ECU) / Bosch EDC: Injector 4 control circuit malfunction

The engine's computer has detected an electrical anomaly in the circuit responsible for firing the fuel injector on cylinder number 4. The underlying condition is typically an open circuit (broken wire/disconnected plug), a short to ground, a short to power, or a failed internal solenoid within the injector itself.

• Iveco Daily
• Eurocargo
• Stralis
• Trakker

1. 1

   Check for multiple injector codes: If codes exist for multiple injectors, the issue is likely a shared wiring harness short or a damaged ECU, not a single injector.

2. 2

   Visual inspection for water ingress: Disconnect the main ECU plugs (e.g., Connector A on the EDC7) and check for green corrosion or moisture, a common issue on Iveco models.

3. 3

   Wiring harness continuity test: Disconnect the plug at Injector 4 and the corresponding plug at the EDC module. Use a multimeter to test the two wires for continuity, high resistance, or a short to ground/power.

4. 4

   Injector solenoid resistance test: Measure the resistance across the two pins on Injector 4. Compare this reading to a known good injector on the engine. If the resistance is completely open (infinite) or shorted (zero), the injector solenoid has failed internally.

1. 1

   Preparation

   Disconnect the negative battery terminal. Thoroughly clean the area around the injectors to prevent dirt from falling into the cylinder head.

2. 2

   Access the injectors

   Remove the engine acoustic cover. On some Tector/Cursor engines, you may need to remove the tappet/valve cover and disconnect oil vapor pipes to access the injectors.

3. 3

   Disconnect lines

   Disconnect the electrical connector from Injector 4. Loosen and remove the high-pressure fuel line connecting the common rail to the injector. Immediately cap the rail and injector ports to prevent contamination. Remove the fuel return (leak-off) line.

4. 4

   Remove the injector

   Remove the injector hold-down clamp/bracket bolt. Carefully pull the injector out. If carbon buildup has seized the injector, use a specialized slide hammer or injector puller. Do not pry against the aluminum cylinder head.

5. 5

   Clean the bore

   Clean the injector bore in the cylinder head. Ensure the old copper sealing washer is removed and the seat is completely spotless.

6. 6

   Install new injector

   Fit a new copper sealing washer and O-ring onto the new injector. Insert the injector into the bore.

7. 7

   Reassembly

   Install the hold-down clamp and torque the bolt to OEM specifications. Reconnect the high-pressure fuel line, return line, and electrical connector.

8. 8

   ECU Coding

   Use a diagnostic scan tool (like Jaltest, Iveco EASY, or equivalent) to program the new injector's IMA (Injector Quantity Adjustment) code into the EDC module. Failure to code the injector will result in rough running and further fault codes.

9. 9

   Testing

   Reconnect the battery, clear the fault codes, prime the fuel system, and start the engine. Check for leaks around the high-pressure fittings.