Diesel Technology major
Diesel Technology: courses, careers, and where to study
Diesel Technology trains you to diagnose, service, and overhaul the diesel engines, fuel-injection systems, and powertrains in heavy trucks, buses, and off-road equipment.
A Diesel Technology program centers on the compression-ignition engines that power Class 8 trucks, transit buses, locomotives, marine craft, construction iron, and standby generators. Coursework moves through diesel engine theory, common-rail and unit-injector fuel systems, turbochargers and intercoolers, and the diesel exhaust aftertreatment that keeps engines compliant, including diesel particulate filters, selective catalytic reduction, and diesel exhaust fluid. You learn to read fault codes over J1939 and J1708 data networks, run guided diagnostics in OEM software such as Cummins INSITE or Detroit Diesel DDDL, and service heavy-duty drivetrains, air brakes, and hydraulics. Where Automotive Technology focuses on the gasoline engines and lighter systems of cars and light trucks, this program works at the scale and pressures of heavy diesel equipment.
Most students enter through a community college or trade-school certificate or associate program, then build experience in fleet shops, dealerships, transit agencies, or construction and agriculture equipment dealers. Many employers value the National Institute for Automotive Service Excellence (ASE) Medium/Heavy Truck (T-series) certifications, and federal EPA Section 609 covers air-conditioning refrigerant handling; some roles ask for a commercial driver's license to road-test vehicles. Apprenticeships and manufacturer training paths are common, and technicians often specialize over time in engines, electrical, or aftertreatment. Pay, demand, and the equipment you see vary by employer, region, and industry, and emissions and electrified-drivetrain technology keep changing. A program is preparation and a foundation for credentials, not a guarantee of any particular job or wage.
In federal data for the closely related occupation of bus and truck mechanics and diesel engine specialists, the U.S. Bureau of Labor Statistics reports a 2024 median wage of $60,640 and projects employment to grow about 2.4% from 2024 to 2034; a high school diploma or equivalent is the typical entry-level education for that occupation. National figures are occupation-wide medians across all experience levels, not starting wages or graduate outcomes.
Academic classification (CIP)
In the federal Classification of Instructional Programs, Diesel Technology maps to CIP 47.0605, Diesel Mechanics Technology/Technician, within the MECHANIC AND REPAIR TECHNOLOGIES/TECHNICIANS family. The official definition:
A program that prepares individuals to apply technical knowledge and skills to repair, service, and maintain diesel engines in vehicles such as automobiles, buses, ships, trucks, railroad locomotives, and construction equipment; as well as stationary diesel engines in electrical generators and related equipment.
Source: U.S. Department of Education (NCES), Classification of Instructional Programs (CIP) 2020. View on nces.ed.gov
What credential Diesel Technology is awarded as
Of the 8,605 Diesel Technology credentials U.S. colleges reported conferring in 2023-24:
- Certificate73%6,260
- Associate27%2,330
- Bachelor's<1%15
This is one of the fields where the answer genuinely depends on where you study: across the 33 states reporting it, certificates run from 13% of credentials in the 10th-percentile state to 98% in the 90th. Check the mix in your state before assuming which credential a program leads to. See the full study.
Credentials conferred in 2023-24, U.S. Department of Education IPEDS completions. A certificate is a different credential from a degree, not a lesser one, and this counts what was awarded rather than what a college currently offers.
What you'll study
- Diesel engine theory, including four-stroke compression ignition, fuel timing, and engine rebuild and overhaul procedures
- High-pressure fuel-injection systems such as common-rail, unit injectors, and mechanical and electronic governors
- Turbocharging, intercooling, exhaust gas recirculation, and intake and air-management diagnostics
- Diesel exhaust aftertreatment: diesel particulate filters, selective catalytic reduction, and diesel exhaust fluid systems and regeneration
- Reading fault codes and electronic data over J1939 and J1708 networks using OEM diagnostic software
- Heavy-duty drivetrains: clutches, manual and automated transmissions, differentials, and driveline service
- Air brake systems, foundation brakes, and inspection to commercial vehicle standards
- Hydraulics, electrical and charging systems, batteries, and starting circuits on heavy equipment
- Shop safety, lockout/tagout, and lifting and supporting heavy vehicles and components
Typical careers
- Diesel mechanic
- Diesel engine specialist
- Truck and bus mechanic
- Heavy equipment mechanic
- Fleet maintenance technician
- Mobile diesel service technician
Typical salary range: Early-career wages vary by employer, region, and experience (BLS, 2024 bus and truck mechanics and diesel engine specialists median $60,640).Ranges are early-career estimates. Any BLS figure shown is the occupation-wide median across all experience levels, not a starting wage, and is informational only.
Related occupations
Occupations the federal CIP–SOC crosswalk associates with Diesel Technology, with what each one pays and how many openings it is projected to average each year. Ordered by projected annual openings, largest first. Linked titles open the full CampusPin career page.
| Occupation | Median pay | Openings / yr | Projected change | Most entrants hold |
|---|---|---|---|---|
| Bus and Truck Mechanics and Diesel Engine Specialists | $60,640 | 26,500 | +2.4% | High school diploma or equivalent |
Crosswalk: U.S. Department of Education (NCES), CIP 2020 to SOC 2018. Pay, openings and projections: U.S. Bureau of Labor Statistics (2024 wages, Employment Projections). 1 of these 1 occupations report a median wage.
“Most entrants hold” is what BLS observes about people already working in the occupation. It is not a legal requirement, not an admission rule, and not a guarantee of entry. Studying Diesel Technology does not guarantee any specific occupation, and many of these roles are entered from several different fields. Projected openings are a projection, not jobs promised.
The federal crosswalk associates only one occupation with Diesel Technology. That is a statement about the field, not about its graduates: a breadth degree is not tied to a particular job, so the crosswalk has little to map. Graduates of this field work across many occupations, and what follows the degree depends far more on the skills and experience built alongside it.
Before you commit to a Diesel Technology major
CampusPin does not rank programs. Use these prompts to pressure-test whether a specific Diesel Technology program fits your goals, they are decision questions, not claims about any school.
Ask the Diesel Technology department
- Which concentrations or specializations are offered, and which faculty lead them?
- What does the typical course sequence look like, and how much is required vs. elective?
- What labs, studios, clinical placements, or research opportunities are available to undergraduates?
- Is there a capstone, thesis, internship, or co-op requirement?
Ask current students & check the curriculum
- How heavy is the workload, and how accessible is the faculty?
- What internships or co-ops did you do, and where do recent graduates end up?
- Does the required curriculum actually match the careers listed above?
- How easy is it to add a minor, double major, or switch tracks later?
Find a Diesel Technology program
CampusPin lists U.S. universities and community colleges by state, tuition, school size, acceptance rate, and campus setting, no account required.
Colleges that awarded the most Diesel Technology credentials
Largest by credentials conferred in 2023-24. This measures the size of the graduating class, not quality, and it is not a ranking.
- WyoTechWY · 473
- Texas State Technical CollegeTX · 321
- Universal Technical Institute of Arizona IncAZ · 262
- Somerset Community CollegeKY · 223
- Elizabethtown Community and Technical CollegeKY · 192
- Gateway Community and Technical CollegeKY · 190
- St Philip's CollegeTX · 185
- University of Northwestern OhioOH · 183
- Universal Technical Institute-Dallas Fort WorthTX · 161
- Universal Technical Institute of Texas Inc.TX · 157
- Bates Technical CollegeWA · 147
- Central Community CollegeNE · 140
Based on credentials this institution reported conferring in the federal IPEDS completions collection for 2023-24. It confirms the field was awarded that year, not that the program currently accepts students, and it covers only the fields CampusPin tracks. Confirm current offerings with the institution.
Where Diesel Technology credentials were awarded
12 states have a distinct enough set of Diesel Technology colleges to be worth its own page.
Search Diesel Technology schools by state
- Diesel Technology in California
- Diesel Technology in Florida
- Diesel Technology in Georgia
- Diesel Technology in Illinois
- Diesel Technology in Maryland
- Diesel Technology in Massachusetts
- Diesel Technology in New York
- Diesel Technology in North Carolina
- Diesel Technology in Pennsylvania
- Diesel Technology in Texas
Related majors
Automotive Technology
Automotive Technology trains you to diagnose, service, and repair the engines, brakes, electrical systems, and drivetrains of cars and light trucks using shop tools and scan equipment.
Automotive Collision Repair
Automotive Collision Repair trains you to straighten unibody and frame damage, replace body panels, and refinish vehicles to factory color and finish after a crash.
Heavy Equipment Operation
Heavy Equipment Operation trains you to run and maintain earthmoving machines like dozers, excavators, motor graders, and scrapers to dig, grade, and shape construction sites.
Commercial Truck Driving
Commercial Truck Driving prepares you to operate tractor-trailers and other commercial vehicles safely, handling pre-trip inspections, cargo, and the rules of interstate hauling.
HVAC Technology
HVAC Technology trains you to install, service, and repair heating, ventilation, air conditioning, and refrigeration systems, blending applied mechanics, electrical work, and hands-on diagnostics.
Put this major in context
The salary above is an occupation-wide median from federal data, not a starting wage or a guarantee. These CampusPin guides and reports help you read it well, see where a Diesel Technology degree can lead, and weigh it against cost and program quality.
Explore Installation & Repair careers
Median pay, job outlook, and the occupations this field covers.
How one major leads to many careers
Why a single Diesel Technology degree can open more than one path, and how to read the occupations above.
Why a median wage is not a starting salary
How to read a BLS median, and why early-career pay usually sits below it.
When accreditation and licensure matter
How program accreditation and state licensure can shape a Diesel Technology path before you enroll.
Does a pricier college pay off?
How college cost lines up with graduation and earnings, an association, not a ranking.
Does picking a major narrow your college list?
Across the federal completions data, most fields barely change which colleges are on the table. Which ones genuinely do.
Certificate or degree?
What credential a field is usually awarded as is mostly set by the field itself, not by the state, with a short list of exceptions.
How this guide is sourced
This is an editorial guide from the CampusPin Editorial Team. Career and wage figures are from the U.S. Bureau of Labor Statistics, occupation-wide medians across all experience levels, not starting wages, and link to each career page. Program availability comes from CampusPin's free institution search; CampusPin does not assert that any specific school offers this exact major until that program data is verified. Last reviewed 2026-06-15. How CampusPin sources data · Report a correction.