Iveco 187 – Engine Control Unit (Engine ECU / EDC): Increased air flow through the exhaust gas recirculation (EGR) valve

The engine's sensors (MAF or MAP) are detecting a higher volume of exhaust gas or intake air than expected when the EGR valve is commanded to open. This indicates that the EGR valve is stuck open, there is a leak in the EGR system, or the valve is failing to regulate flow properly.

• Iveco Daily
• Iveco Stralis
• Iveco Eurocargo
• Iveco Trakker
• Iveco N67
• Iveco F2BE

1. 1

   Check the EGR valve for severe carbon buildup, which is the most common cause of the valve sticking open and allowing excess flow.

2. 2

   Check the Mass Air Flow (MAF) and Manifold Absolute Pressure (MAP) sensors, as a faulty sensor reading can falsely trigger code 0187.

3. 3

   Inspect the wiring harness and electrical connectors going to the EGR valve actuator for shorts, corrosion, or breaks.

4. 4

   Check the EGR cooler, EGR pipes, and intake manifold for any vacuum or exhaust leaks that could skew airflow readings.

1. 1

   Disconnect the vehicle's negative battery terminal to prevent electrical shorts and ensure the engine is cool.

   Preparation step before beginning EGR valve replacement.

2. 2

   Locate the EGR valve assembly on the engine.

   Typically mounted near the intake manifold or exhaust manifold, though location varies by engine model.

3. 3

   Unplug the electrical connector from the EGR valve actuator.

   Disconnect electronics.

4. 4

   Unbolt the EGR cooler pipes and exhaust gas return pipes connected to the valve.

   Remove plumbing.

5. 5

   Remove the mounting bolts securing the EGR valve to the engine block or manifold and extract the valve.

   Remove the valve.

6. 6

   Thoroughly clean the mounting surfaces of old gasket material and carbon deposits.

   Clean mating surfaces.

7. 7

   Install the new EGR valve using new gaskets/seals.

   Torque the mounting bolts to the manufacturer's specifications.

8. 8

   Reconnect the EGR piping and plug the electrical connector back into the actuator.

   Reassembly.

9. 9

   Reconnect the battery, use an Iveco-compatible OBD-II diagnostic tool to clear fault code 0187, and perform a test drive.

   Clear codes and ensure the code does not return.