Iveco 01F8 – Engine Control Unit (ECU) / EDC: Incorrect signal in the exhaust gas temperature sensor circuit

The Engine Control Unit (ECU) is receiving an implausible, out-of-range, or missing signal from the Exhaust Gas Temperature (EGT) sensor.

• Iveco Daily
• Iveco Stralis
• Iveco Eurocargo
• Iveco Tector
• Iveco Trakker
• Iveco Eurotrakker

1. 1

   Inspect the EGT sensor and its wiring harness for melted wires, chafing, or physical damage caused by road debris or extreme exhaust heat

2. 2

   Disconnect the EGT sensor connector and check for water ingress, corrosion, or bent pins

3. 3

   Using a multimeter, check the resistance of the EGT sensor to rule out an open circuit or a dead short

4. 4

   Check the voltage supply and ground on the harness side of the connector (with ignition on) to ensure the EDC is sending the correct 5V reference voltage

5. 5

   Use an OBD2 diagnostic scanner to view live EGT data; if the sensor reads a fixed default value (e.g., -40°C or 1000°C), the sensor or circuit is dead

1. 1

   Preparation

   Ensure the vehicle is parked on a level surface, the ignition is turned off, and the battery is disconnected. Crucially, allow the exhaust system to cool completely to prevent severe burns.

2. 2

   Locate the Sensor

   Find the faulty EGT sensor on the exhaust system.

3. 3

   Disconnect the Electrical Connector

   Unplug the sensor's pigtail connector from the main engine wiring harness.

4. 4

   Remove the Sensor

   Spray penetrating oil (like WD-40 or PB Blaster) on the threads of the sensor and let it sit for a few minutes. Use a specialized EGT sensor socket or a flare-nut wrench to carefully unscrew the sensor from the exhaust bung.

5. 5

   Install the New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if it does not come pre-coated). Thread it in by hand to avoid cross-threading, then tighten it to the manufacturer's specified torque.

6. 6

   Reconnect

   Plug the electrical connector back into the wiring harness, ensuring it clicks securely into place. Route the wire away from direct contact with the hot exhaust pipe.

7. 7

   Clear Codes

   Reconnect the battery. Connect a diagnostic scan tool to the vehicle's OBD port and clear the 01F8 fault code.

8. 8

   Test Drive

   Start the engine and monitor the live EGT data on the scanner to confirm the new sensor is reading fluctuating, realistic temperatures.