Diesel Mechanic Certification


Many industries rely on diesel technology to power their operations.

Those with a passion for diesel engines can pursue careers as diesel mechanics — also known as diesel technicians — and work hands-on with these systems.

Having the right training under your belt is necessary. In most cases, prior education is preferred when entering the workforce. That’s where Universal Technical Institute’s (UTI) Diesel Technology program comes in, helping students gain the hands-on skills and training employers are looking for.1,18

And if you want to take your education even further, the next step would be to look into diesel mechanic certification.

Interested in learning more about how to become a certified diesel mechanic? Keep reading!

What Are Diesel Mechanic Certifications?

Diesel technician certifications are documents that show that someone has demonstrated the required knowledge in specified areas. While you can work in the industry without having certifications, they can help improve your outlook when it comes to employment and salary.

One of the top groups certifying mechanics is the National Institute for Automotive Service Excellence, or ASE. Since 1972, ASE has been offering a wide range of certification tests for automotive and diesel technicians that build upon the foundational education that can be received at trade schools like Universal Technical Institute.

Benefits to getting certified include recognition and respect in the industry that can help technicians with job searches or with advancing their careers. Those who need repairs or maintenance for their diesel machinery know they can count on an ASE-certified technician to get the job done right.

What is a Certified Diesel Mechanic?

A certified diesel mechanic is a professional who has completed the necessary training and gained the experience needed to earn certification documents confirming their skill level for professional industry work. Not all certifications have the same requirements.

To become ASE certified, a diesel mechanic must pass a series of exams that assess their knowledge and skills. Before they can sign up for these exams, they must also show proof that they have two years of real-world work experience under their belt. To maintain their ASE certification, diesel technicians must also retest every five years and prove how current their industry knowledge is.

Read: Diesel 101: History & Invention of the Diesel Engine

Importance of Diesel Mechanic Certification

While certification isn’t federally mandated, many employers require or prefer their technicians to be certified. That’s because these documents help ensure their technicians have the knowledge and skills needed to perform their duties correctly.

Benefits of Becoming a Certified Diesel Mechanic

Long story short, certification matters because skilled diesel technicians are in demand. One way for aspiring technicians to develop key industry skills is to get training on the job. Of course, getting a job without any prior experience can be a trickier process, which is where technical training comes in!

Luckily for students attending UTI’s 45-week Diesel Technology program,7 completing our training master certified by the ASE Education Foundation also counts toward one of the two years of work experience required to sign up for ASE exams. This way, program graduates have skills necessary for working on diesel tech.

After passing the exams and earning their certification, diesel technicians can show employers that they’re ASE certified! Employers like to hire ASE-certified techs since less time will be devoted to on-the-job training and more time to working on diesel technology.

Read: How to Become a Diesel Mechanic: Qualifications & Requirements

Preparing for Certification Tests

It’s important to take the time to prepare well for taking certification tests. Receiving core diesel training in a program accredited by the ASE Education Foundation can provide you with a great starting point.16

UTI’s Diesel Technology program trains students how to diagnose and repair diesel engines as well as medium/heavy-duty chassis subsystems in as little as 45 weeks and is offered at campuses nationwide. Students also have the option to further their education with specialized training programs to gain skills needed to service trucks and engines from big names in the industry like Cummins,46 Peterbilt15 and Daimler Truck.

Diesel mechanic certification requirements also include proof of working in the industry or relevant training. Graduates of the diesel program at UTI can substitute the training they received for one of the two years of work experience that are required for testing to become ASE certified.

When it comes to test prep, the ASE website has several resources that can help you feel confident when the time comes:

  • Practice tests: These online tests help familiarize you with ASE-style tests before jumping into the real thing. Feedback is also provided with a performance report that provides explanations for correct and incorrect answers.
  • Study guides: Study guides are available for each test series and help provide more details on individual tests within the series, such as the major content areas and the amount of time given to complete a test. Sample questions are also provided.
  • Testing demo: A free testing demo lets you get a sense of what an actual test is like within the ASE testing platform and explains the functions and features within the system.

By utilizing these resources and by drawing on the knowledge you already have from completing a diesel training program, you can feel more prepared to take certification tests.

Read: Light-Duty vs. Heavy-Duty Diesel Training: Which is Right for Me?

Types of Diesel Certification Tests

ASE offers several medium/heavy truck tests that cover the skills needed to service and repair different systems of Class 4 through Class 8 trucks and tractors.

The tests offered for medium- and heavy-truck technicians are:

  • T1: Gasoline Engines
  • T2: Diesel Engines
  • T3: Drive Train
  • T4: Brakes
  • T5: Suspension & Steering
  • T6: Electrical/Electronic Systems
  • T7: Heating, Ventilation & Air Conditioning (HVAC)
  • T8: Preventative Maintenance Inspection

There are also other diesel engine areas that ASE offers certification areas for, including light trucks, transit buses, school buses, truck equipment and advanced-level specialties, such as the electronic diesel engine diagnosis specialist certification test (L2).

ASE certifications are written by industry professionals, from working technicians to manufacturers and educators. The questions are entirely job-related and test the skills needed for servicing diesel vehicles.

Master Diesel Mechanic Certification

Once certification is achieved in the required testing areas for the series, Master Technician status is earned. Master medium/heavy-truck technicians are those certified in tests T2 through T8. It’s important to remember that there are recertification tests that are required every five years to maintain Master Technician status.

Certified Diesel Mechanic Salary and Job Outlook

Having a sense of the salary potential and outlook for a career can help ensure it’s the right path to pursue. While there is no information specific to salary and job outlook for certified diesel technicians, general information about diesel mechanics can help give a starting estimate. The U.S. Bureau of Labor Statistics (BLS) is a great resource that can help give an idea of what to expect as far as median annual salary in various fields.

According to the BLS, the median annual salary for bus and truck mechanics and diesel engine specialists in the United States was $58,970 in May 2023.29 This means half of diesel technicians earned more and half earned less. Keep in mind that salary depends on several factors, including experience, employer, demand and cost of living in the area.

Total diesel technician employment is also expected to be 305,800 by 2031.48 With additional certifications on a résumé, technicians have more to offer potential employers!

Can I Become a Certified Diesel Mechanic Without Prior Experience?

Every diesel mechanic had their start somewhere. However, without documented work experience, it can be difficult to land a job in the first place.

That’s where UTI’s Diesel Technology training program comes in! It’s a great place to kick-start your education journey and you don’t need prior work experience to apply.

Students here can train hands-on in labs outfitted with industry-standard equipment and learn key diesel technology skills from the ground up.18 Completing our Master Certified Diesel Technology program also fulfills one year of the two-year work experience prerequisite for ASE exams.

To help complete that remaining year needed to sign up for ASE exams, diesel students can also speak with our Career Advisors to pursue part-time work in the field while enrolled in their studies (also possible through participation in our Early Employment Program for eligible students) or seek full-time industry employment after graduating from their program.

After completing the work experience prerequisite and passing ASE exams, you’re officially a certified diesel mechanic!1

Read: After 35+ Years in the Industry, Diesel Pro Turns to Teaching

Diesel Mechanic Certification FAQs

What is a Certified Diesel Mechanic?

Getting ASE-certified as a diesel mechanic is about clocking in real-world experience, passing those ASE exams and making sure to stay on top of the game by retesting and passing those exams every five years.

How do I Become a Certified Diesel Mechanic?

Pursuing a career in diesel mechanics can be made easier with Universal Technical Institute's Diesel Technology training program – no prior experience needed. Completing the program and gaining additional work experience helps qualify you for ASE testing needed to become a certified diesel mechanic.1

Are There Different Types of Diesel Mechanic Certifications?

Yes! There are various types of diesel mechanic certifications. The ASE offers a variety of tests, such as certifications for various systems in medium and heavy trucks, light trucks, transit buses and school buses, as well as advanced-level specialties such as the Electronic Diesel Engine Diagnosis Specialist Certification Test (L2). After earning certifications in the required testing areas, a technician can be eligible to seek Master Technician status.

What are the Benefits of Becoming a Certified Diesel Mechanic?

Certification shows you've got in-demand skills! It also means you can hit the ground running without needing much on-the-job training.

How Long Does it Take to Become a Certified Diesel Mechanic?

There are many ways to become a certified diesel mechanic, but some ways are more effective than others. By training at Universal Technical Institute’s 45-week Diesel Technology program, you can obtain one of the two years of work experience required by the ASE and be eligible to take its exams!7

What Skills are Necessary to Obtain Diesel Mechanic Certification?

Now, if we're talking about the nitty-gritty skills you need, it's not just about book smarts. Sure, you need to know your stuff when it comes to servicing medium/heavy trucks, but it's not all theory.

You've got to show you can apply that knowledge in the real world. That means demonstrating your proficiency and skill level specific to diesel engines.

And don't forget, the ASE certification exams aren't a walk in the park. They're challenging and require both knowledge and practice to earn a passing score. So, you'll want to make sure you're well-prepared before you sit for them.

In short, becoming an ASE Certified Diesel Mechanic is all about having the right mix of theoretical knowledge, practical skills, hands-on experience and passing exams. But once you've got it, it's a great way to show employers you've got what it takes to work in the field!

Are There Specific Educational Qualifications Needed for Diesel Mechanic Certification?

No, there aren’t. However, UTI’s Master Certified Diesel Technology program can help when pursuing ASE certification!

Can I Become a Certified Diesel Mechanic Without Prior Experience?

To get certified by the ASE, you need one year of work experience to sign up for and pass its exams!

Are There Ongoing Requirements or Renewals for Diesel Mechanic Certification?

Not all certification processes are the same. With the ASE, certified technicians must retest every five years.

Read: From Student to UTI Miramar’s First BMW FastTrack Instructor

Start Your Journey Toward Diesel Certification at UTI

If obtaining your diesel mechanic certifications sounds like the right move for you, enrolling in the Diesel Technology program at UTI is a great first step. Graduates get training that they can substitute for one of the two years of work experience needed to become ASE certified and have a foundational knowledge to continue to build upon.

Find out more when you request more information or connect with an Admissions Representative at 1-800-834-7308 today!

UTI Campuses That Offer Diesel Mechanic Training

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1 ) UTI is an educational institution and cannot guarantee employment or salary.
2 ) For program outcome information and other disclosures, visit www.uti.edu/disclosures.
7 ) Some programs may require longer than one year to complete.
15 ) Manufacturer-paid advanced training programs are conducted by UTI on behalf of manufacturers who determine acceptance criteria and conditions. These programs are not part of UTI’s accreditation. Programs available at select locations.
16 )  Not all programs are accredited by the ASE Education Foundation.
18 ) UTI now offers all of its automotive, diesel, motorcycle and marine technician training in a blended-learning format consisting of online lecture courses along with in-person, hands-on lab training.
29 ) UTI’s Diesel Technology Program prepares graduates for entry-level positions using the provided training, primarily as diesel technicians. Estimated annual salary shown above is for Bus and Truck Mechanics and Diesel Engine Specialists as published in the U.S. Bureau of Labor Statistics’ May 2023 Occupational Employment and Wages. Entry-level salaries are lower for UTI graduates. UTI is an educational institution and cannot guarantee employment or salary. UTI graduates’ achievements may vary. Individual circumstances and wages depend on economic factors, personal credentials, work experience, industry certifications, the location of the employer, and their compensation programs. Some UTI graduates get jobs within their field of study in positions other than as diesel truck technicians, including in industries such as heavy equipment repair, power generation, and agriculture. Salary information for the Commonwealth of Massachusetts: The average annual entry-level salary range for persons employed as Bus and Truck Mechanics and Diesel Engine Specialists (49-3031) in the Commonwealth of Massachusetts is $48,980 (Massachusetts Labor and Workforce Development, May 2022 data https://lmi.dua.eol.mass.gov/lmi/OccupationalEmploymentAndWageAllIndustries/OEWResult?A=01&GA=000025&OG=493031&Dopt=TEXT). Salary information for North Carolina: The U.S. Department of Labor estimates the hourly median wage for skilled diesel technicians in North Carolina is $25.28 (Bureau of Labor Statistics, U.S. Department of Labor, May 2023 Occupational Employment and Wages, Bus and Truck Mechanics and Diesel Engine Specialists). The Bureau of Labor Statistics does not publish entry-level salary data. However, the 25th and 10th percentile of hourly earnings in North Carolina are $21.55 and $18.00, respectively.
46 ) Students must maintain a minimum 3.0 GPA.
48 ) The U.S. Bureau of Labor Statistics projects that total national employment for Bus and Truck Mechanics and Diesel Engine Specialists will be 294,100 by 2032. See Table 1.2 Employment by detailed occupation, 2022 and projected 2032, U.S. Bureau of Labor Statistics, www.bls.gov, viewed November 16, 2023. UTI is an educational institution and cannot guarantee employment or salary.

Universal Technical Institute of Illinois, Inc. is approved by the Division of Private Business and Vocational Schools of the Illinois Board of Higher Education.


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