International 4700 DT466: Addressing the 45 MPH Speed Limitation

[MikePhua]

The International 4700 series truck equipped with the DT466 engine is a reliable workhorse used in various commercial and industrial applications. However, some owners have experienced an issue where the truck is governed to a maximum speed of 45 MPH, which can be problematic for highway driving or other high-speed tasks. This article outlines the potential causes for this limitation and offers solutions to address the problem.
Possible Causes of the 45 MPH Speed Limitation
The issue of the truck being governed at 45 MPH is often related to one of the following factors:

1. Speed Governor Settings
   • The most common reason for a speed limitation in trucks like the International 4700 is the speed governor settings. Many commercial trucks are equipped with speed governors to limit the maximum speed for safety, fuel efficiency, and regulatory compliance. These governors can be set through the truck's ECM (Engine Control Module) to a specific speed, such as 45 MPH, to meet fleet management or legal requirements.
     
2. Faulty ECM Calibration
   • In some cases, the problem could be linked to an issue with the ECM calibration. If the ECM has been improperly calibrated or there is an error in its programming, it may incorrectly limit the truck's maximum speed. A technician may need to recalibrate or reprogram the ECM to restore the truck's full potential.
     
3. Engine or Transmission Issues
   • Mechanical issues, such as engine problems, transmission malfunctions, or fuel delivery restrictions, can also cause the truck to feel like it is being limited to a certain speed. If the engine or transmission is not performing optimally, the truck may struggle to accelerate beyond 45 MPH. These issues often stem from faulty components, such as the fuel injectors, turbocharger, or transmission controls.
     
4. Electronic or Sensor Malfunctions
   • The International 4700's sensors, which monitor various engine parameters, may malfunction and cause the truck to behave as if it is governed to a lower speed. Sensors such as the throttle position sensor or vehicle speed sensor may send incorrect signals to the ECM, resulting in the truck not reaching higher speeds.
     

How to Address the 45 MPH Speed Limitation
To resolve the issue of the speed limitation on the International 4700 DT466, consider the following steps:

1. Check the Speed Governor Settings
   • The first step is to check if the speed governor has been intentionally set to limit the vehicle's speed. This can typically be done by accessing the truck's ECM using specialized diagnostic tools. If the governor is set too low, it can be reprogrammed to allow for a higher top speed. If you are unsure how to access or adjust these settings, a qualified technician will be able to do it for you.
     
2. Recalibrate the ECM
   • If the ECM has been improperly calibrated, it can be reset or recalibrated to restore the truck's performance. A mechanic or dealership specializing in International trucks should be able to perform this adjustment using diagnostic equipment. Recalibrating the ECM can resolve programming errors that are affecting the truck's speed.
     
3. Inspect the Engine and Transmission
   • Conduct a thorough inspection of the engine and transmission systems. Look for signs of wear, damaged components, or leaks. If the fuel injectors or turbocharger are malfunctioning, replacing or repairing them could improve performance and resolve speed limitations. Additionally, ensure that the transmission is functioning properly and shifting smoothly.
     
4. Diagnose Sensor Issues
   • If the issue persists after addressing the speed governor settings and ECM calibration, check the sensors connected to the ECM. Faulty sensors, such as the throttle position sensor, can cause incorrect readings that limit the truck’s speed. Replace any malfunctioning sensors to ensure accurate readings and smooth engine performance.
     

Preventive Measures
To prevent similar issues from arising in the future, consider these tips for maintaining your International 4700 DT466:

1. Regular Maintenance
   • Perform regular maintenance on the engine, transmission, and other critical systems. Regular oil changes, filter replacements, and fluid checks will keep your truck running smoothly and help prevent mechanical failures.
     
2. Monitor ECM and Sensor Health
   • Keep an eye on the health of the ECM and sensors by periodically performing diagnostic checks. This can help identify and address any calibration or sensor issues before they lead to performance problems.
     
3. Consult a Professional Technician
   • If you are unsure about how to diagnose or fix the speed limitation issue, consulting with a professional technician is always a good idea. An experienced technician can quickly identify the root cause and implement a solution to restore full speed to your vehicle.
     

Conclusion
The speed limitation of 45 MPH in the International 4700 DT466 is most commonly related to the speed governor settings, ECM calibration, or mechanical issues. By checking the speed governor, recalibrating the ECM, and ensuring the engine and transmission are functioning properly, most of these problems can be resolved. Regular maintenance and diagnostics are key to keeping your truck running at its optimal performance and avoiding issues in the future.