Iveco 159 – Engine Control Unit (ECU) / EDC (Electronic Diesel Control): Circuit Malfunction of the fuel pump (high pressure pump)

Indicates an electrical circuit failure or malfunction related to the high-pressure fuel pump's control system, specifically pointing to the fuel pressure regulator (metering valve, M-prop, or DRV control valve) mounted on the high-pressure pump. The system detects that the electrical circuit controlling the fuel pressure is either open, shorted, or operating outside of expected parameters.

• Iveco Daily
• Iveco Eurocargo
• Iveco Stralis

1. 1

   Inspect the wiring harness and the electrical connector going to the fuel pressure regulator on the high-pressure pump for corrosion, moisture ingress, or broken wires

2. 2

   Verify that the low-pressure electric lift pump is supplying adequate fuel to the filter and the high-pressure pump

3. 3

   Check the fuel filter for blockages or heavy contamination

4. 4

   Perform a return leakage test on the fuel injectors to check for excessive fuel returning to the tank

5. 5

   Check the resistance of the fuel pressure regulator valve with a multimeter to ensure the internal solenoid is not shorted or open

1. 1

   Disconnect battery

   If replacing the Fuel Pressure Regulator (Metering Valve): Disconnect the negative battery terminal.

2. 2

   Locate pump

   Locate the high-pressure fuel pump at the front/side of the engine block. The pressure regulator is bolted directly to the pump body.

3. 3

   Clean area

   Thoroughly clean the area around the regulator to prevent any dirt (even microscopic particles) from entering the pump.

4. 4

   Disconnect connector

   Disconnect the electrical connector from the regulator.

5. 5

   Remove screws

   Remove the retaining screws (usually Torx or Allen) holding the regulator to the pump.

6. 6

   Remove regulator

   Carefully twist and pull the regulator out of the pump housing.

7. 7

   Install new regulator

   Lubricate the O-rings on the new regulator with clean diesel fuel and press it into the pump housing.

8. 8

   Secure regulator

   Install and torque the retaining screws, then reconnect the electrical plug.

9. 9

   Disconnect battery and clear access

   If replacing the High-Pressure Fuel Pump: Disconnect the battery and remove any intake piping or brackets obstructing access to the pump.

10. 10

    Disconnect metering valve

    Disconnect the electrical connector from the pump's metering valve.

11. 11

    Disconnect fuel lines

    Disconnect the low-pressure feed/return lines and the high-pressure steel line running to the common rail. Cap all open ports immediately to prevent contamination.

12. 12

    Remove access cover

    Remove the pump drive gear/sprocket access cover (if applicable) and lock the engine timing if required by the specific engine manual.

13. 13

    Remove pump

    Unbolt the pump from the engine block/timing case and remove it.

14. 14

    Install new pump

    Install the new pump, torque the mounting bolts to OEM spec, and reattach the drive gear.

15. 15

    Reconnect lines and connectors

    Reconnect all fuel lines and electrical connectors.

16. 16

    Prime fuel system

    Prime the fuel system by cycling the ignition key to the 'ON' position several times (allowing the low-pressure pump to run) before attempting to crank the engine.

17. 17

    Clear fault codes

    Clear the EDC fault codes using a diagnostic scanner or the Iveco blink-code clearing procedure.