About This Course

Modern diesel engines rely on advanced aftertreatment systems to meet today’s strict emissions standards - and when these systems fail, downtime can be both costly and complex to resolve. This hands-on, technician-focused course is designed to give you the knowledge and confidence to diagnose, troubleshoot, and maintain Cummins aftertreatment emission systems with precision.

Through real-world examples and step-by-step instruction, you’ll explore the full range of Cummins aftertreatment components, including Diesel Oxidation Catalysts (DOC), Diesel Particulate Filters (DPF), and Selective Catalytic Reduction (SCR) systems. The course goes beyond theory - equipping you with proven strategies to tackle common fault codes, reduce repeat failures, prevent unnecessary part replacements, and reduce downtime.

Whether you're working in a fleet maintenance shop, a dealership, or as an independent heavy-duty technician, this course will sharpen your troubleshooting skills and help you minimize vehicle downtime. You'll also receive a VieTech certification upon completion, showing your proficiency in our Aftertreatment emission systems diagnostics course. Stay ahead of evolving emission technologies and ensure your shop can handle Cummins-powered vehicles with confidence.

The free preview of this course includes an in-depth breakdown of the course content and expectations, a look at early training modules of the course, and a randomized 15-minute video snippet of training from the paid course. Begin the free preview now using the button above to start learning about Cummins Aftertreatment Emission System Diagnostics now!

What You Will Learn

  • Understand Operation

    Gain a deep understanding of the design, function, and evolution of diesel aftertreatment systems—from early EPA Tier 3 technologies to modern Tier 4 Final emissions standards. Learn how Cummins has integrated components like the Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), and Selective Catalytic Reduction (SCR) systems to meet environmental regulations. By the end of this course, you'll have the technical background to identify how these systems operate under various load and regeneration conditions, and how each component contributes to emission reduction.

  • Troubleshoot Fault Codes

    Master the step-by-step process for identifying, diagnosing, and resolving aftertreatment fault codes on Cummins diesel engines. You'll learn how to interpret trouble codes using tools like Cummins INSITE, analyze live data from NOx and temperature sensors, and perform forced regenerations when needed. The course teaches how to distinguish between symptom-based and root cause-based troubleshooting to reduce guesswork, avoid misdiagnoses, and improve repair efficiency.

  • Reduce Downtime

    Discover proven strategies to reduce vehicle and equipment downtime caused by aftertreatment system failures. Learn how to implement proactive maintenance techniques, interpret early warning signs of component wear, and avoid repeat issues through effective preventative diagnostics. By addressing common problems with DEF systems, clogged DPFs, and failed sensors, you’ll help fleets stay on the road longer and reduce costly unscheduled repairs—saving time, money, and productivity.

Training Previews, Downloadables & Exams

    1. Student Workbook Download

    2. Watch Now - Cummins Aftertreatment System Virtual Classroom Recording

    1. Knowledge Check

Course Details

  • $349.00
  • 7 lessons
  • 4 hours of video content
  • Certification provided upon completion

Frequently Asked Questions (FAQ)

  • How long after signing up until I can start training?

    The Cummins Aftertreatment Emission Systems Diagnostics virtual classroom will be immediately available once you've purchased the course! You can begin learning how to diagnose problems based on diesel engine fault codes, operate within EPA regulations on emissions, and start getting certified now!

  • What is the Cummins aftertreatment system and how does it work?

    The Cummins aftertreatment system is designed to reduce diesel emissions using components like the Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), and Selective Catalytic Reduction (SCR) system. It treats exhaust gases after they leave the engine to meet emissions standards.

  • Can I diagnose Cummins aftertreatment issues or complete this course without dealership tools?

    Yes. While dealer software like Cummins INSITE is ideal, there are reliable aftermarket scan tools that can read aftertreatment fault codes, perform forced regens, and monitor system performance.

  • How do you diagnose aftertreatment faults on Cummins engines?

    Diagnosing Cummins aftertreatment faults involves reading fault codes, analyzing sensor data, and performing regen cycles. This course teaches step-by-step methods using industry tools and real-world scenarios.

  • What makes this Cummins Aftertreatment Diagnostics Course different?

    VieTech’s course offers hands-on, real-world diesel training with a focus on Cummins emission system troubleshooting, not just theory. Join over 1,000 happy certified techs, and learn to diagnose, repair, and verify fixes with confidence.

  • What can I expect to learn from this training course?

    This training will focus on EPA Heavy-Duty Diesel Engine emissions regulations and corresponding technology utilized by engine manufacturers to meet the requirements. The content delivered will directly relate to the developments, product changes, troubleshooting and service procedures surrounding current diesel engine aftertreatment emission control systems used across all major manufacturers. - Understanding of Diesel Engine Emission Control History & Technology Advances - Overview of EPA 2004 – 2016 tailpipe emission regulations - Overview of GHG CO2 emission regulations - Diesel exhaust gas recirculation (EGR) theory and operation - In-depth understanding of exhaust Aftertreatment components, theory and operation - Diesel Oxidation Catalyst (DOC) Diesel Particulate Filter (DPF) - Selective Catalytic Reduction (SCR) Catalyst - Diesel Exhaust Fluid (DEF) System HD OBD & Fault Troubleshooting Logic - Single Module Aftertreatment Systems - UL2 DEF Dosing System - Understanding of maintenance, troubleshooting techniques and diagnostic tests - Diagnosis of engine faults and symptoms using current troubleshooting software

  • How do I troubleshoot SCR problems on a Cummins diesel engine?

    To troubleshoot Cummins SCR system issues, check DEF fluid quality, inspect NOx sensors, and review fault codes using Cummins INSITE or similar diagnostic tools. Poor DEF dosing or sensor errors are often to blame. You will learn all of this, plus much, much more in this expert-led certification course.

What Certified Technicians Are Saying About VieTech Training

Chris Bouius

Kevin provides a great course with information and practical experience that every mechanic working on aftertreatment systems will benefit from, no matter their level of previous experience. Would highly recommend this course. Wish I knew what I have now learned years ago as it would of made my job much easier and equipment run trouble free and at a much lower maintenance cost. This course should be the new industry standard. Well done Kevin keep up the great work.

Boundary Sentinel

Outstanding focused curriculum delivered with technical and educational proficiency. Techs will benefit from Kevin’s instruction both in approach and efficiency with modern diesel/CNG/propane and aftertreatment technologies. Highly recommend VieTech to all employers looking for a cost effective, modern and complete training package for their employees.

Ryan Bester

This course should be given to all diesel techs. After dealing with these systems for a decade I finally feel comfortable with my knowledge to repair these systems not only properly but efficiently. Thanks to Kevin for a great course.

Allan Steidle

Great training for the diesel engine technician with practical solutions to modern emission technology malfunctions. A must for technicians to keep up with current standards on their fleet equipment. Kevin is knowledgeable and able to apply theory with real world applications and diagnosis in a language technicians will appreciate. I would highly recommend Vietech training and Kevin for your training needs on diesel engine emission present day applications.

Instructor(s)

Senior Training Instructor Kevin Vieth

Kevin is a Red Seal Service Tech with extensive experience as an industry training instructor. Kevin has provided technician certification training for multiple industry leaders, including Cummins, Hunter Engineering and BCIT.

Get Certified in Aftertreatment Emission Systems Diagnostics Today

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