The message “Exhaust (SCR/DEF) service required” can be a frustrating experience for any truck owner. This article will guide you through diagnosing and troubleshooting this issue using Cummins Insite software, focusing on the necessary steps to pinpoint the root cause. We’ll explore common culprits like the DEF doser valve and NOx sensors, and discuss how Insite can help you determine the best course of action.
Understanding the “Exhaust (SCR/DEF) Service Required” Message
This warning indicates a problem within the Selective Catalytic Reduction (SCR) system, responsible for reducing NOx emissions. The Diesel Exhaust Fluid (DEF) system, integral to the SCR process, might also be involved. When this message appears, it’s crucial to use diagnostic tools like Cummins Insite to identify the specific fault codes triggering the warning.
Utilizing Cummins Insite for Diagnostics
Cummins Insite provides detailed fault code information, guiding you toward the problem’s source. Connecting your laptop with Insite to the vehicle’s diagnostic port allows you to retrieve active and inactive fault codes. These codes provide specific insights into the system malfunction. For instance, code 3568 points to a potential issue with the DEF dosing valve, while code 3718 suggests a problem with the intake NOx sensor.
Common Causes and Troubleshooting Steps
1. DEF Doser Valve Issues (Fault Code 3568): A malfunctioning DEF doser valve is a frequent cause of the “Exhaust (SCR/DEF) service required” message. Insite enables you to perform the “Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test.” This test, conducted with the valve removed and directed into a container, assesses the valve’s spray pattern and output volume, helping determine if it’s clogged, malfunctioning, or operating within specifications.
2. NOx Sensor Problems (Fault Code 3718): A faulty NOx sensor can also trigger the warning. Cummins Insite can help confirm this by providing specific data related to the sensor’s readings. If the sensor is out of calibration or malfunctioning, replacement is typically necessary. Consult Cummins QuickServe for detailed diagnostic procedures related to this fault code.
3. Fuses and Relays: Before replacing components, Insite guides you to check the related fuses and relays. A blown fuse or faulty relay can disrupt power supply to critical components within the SCR and DEF systems. Cummins QuickServe provides detailed schematics and locations of these components for your specific engine model.
Repair Validation with Insite
After completing repairs, Insite plays a crucial role in validating the fix. By commanding DEF dosing and observing the system’s response, you can confirm the repair’s effectiveness. This process ensures the issue is resolved and the system is functioning correctly. Utilize Insite’s diagnostic tests to monitor relevant parameters and ensure all values are within the acceptable range.
Conclusion
Cummins Insite is an invaluable tool for diagnosing and resolving the “Exhaust (SCR/DEF) service required” message. By providing specific fault codes, guiding troubleshooting steps, and allowing for repair validation, Insite empowers you to address the issue effectively. Utilizing resources like Cummins QuickServe alongside Insite will provide comprehensive information for accurate diagnosis and repair. Remember to always consult official documentation and follow recommended procedures for your specific engine model.
