Iveco 151 – EDC7: High level signal circuit pressure sensor rail

The engine control module is receiving a voltage signal from the fuel rail pressure sensor that exceeds the maximum allowable threshold, typically pointing to an electrical issue such as a short to positive, an open ground wire, or an internally shorted sensor.

• Iveco Daily
• Iveco Stralis
• Iveco Eurocargo
• Case 621G
• Case 721F

1. 1

   Inspect the fuel rail pressure sensor connector for internal diesel fuel leaks causing a short circuit.

2. 2

   Test the 3-wire sensor pigtail wiring harness for chafing, a short to power, or a broken ground wire.

3. 3

   Inspect the low-pressure fuel return lines above the fuel tank and from the injectors for blockages or kinks.

4. 4

   Use a diagnostic tool to read live fuel pressure data to rule out a sticking fuel pressure regulator (M-Prop valve).

1. 1

   Preparation

   Turn off the ignition and disconnect the negative battery terminal.

2. 2

   Gain Access

   Depending on the model, you may need to move components out of the way. On some Iveco Daily models, the sensor is located under the coolant reservoir. If so, unscrew the retaining nuts (typically 10mm) and carefully move the reservoir aside without disconnecting the coolant hoses.

3. 3

   Remove the Sensor

   Locate the fuel rail pressure sensor at the end of the high-pressure common rail. Disconnect the electrical plug. Use a wrench to unscrew the sensor from the rail.

4. 4

   Install the New Sensor

   Thread the new Bosch/Iveco sensor into the fuel rail and tighten it to the manufacturer's torque specification. Do not use sealants, as the sensor seals via a machined mating surface.

5. 5

   Reassembly

   Reconnect the electrical plug and reinstall any components (like the coolant reservoir) that were moved. Reconnect the battery.

6. 6

   Clear Codes and Prime

   Clear the EDC fault codes using a diagnostic scan tool or the Iveco dashboard blink-code button. Cycle the ignition to prime the fuel system, start the engine, and check for leaks at the rail.