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 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. Linked titles open a CampusPin career page with BLS pay and outlook data; others are listed for reference.

Source: U.S. Department of Education (NCES), Crosswalk: CIP 2020 to SOC 2018. A program of study does not guarantee any specific occupation.

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?
Accreditation & licensure: Many employers recognize ASE Medium/Heavy Truck (T-series) certifications, and refrigerant work may require EPA Section 609 certification. Confirm a specific program's credentials, manufacturer training, and any commercial driver's license expectations directly with the school and with prospective employers in your region.
Degree level & graduate study: Many Diesel Technologycareers are open with a bachelor's degree, but some, such as research, advanced-practice, or licensure-track roles, require a master's or doctorate. Check the typical entry-level education on each linked career page above before assuming a bachelor's is enough.

Find a Diesel Technology program

CampusPin lists U.S. universities and community colleges that offer Diesel Technology programs. Filter by state, tuition, school size, acceptance rate, and campus setting, no account required.

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Related majors

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 pages help you read it well and weigh a Diesel Technology degree against its cost.

Explore Installation & Repair careers

Median pay, job outlook, and the occupations this field covers.

Why a median wage is not a starting salary

How to read a BLS median, and why early-career pay usually sits below it.

Does a pricier college pay off?

How college cost lines up with graduation and earnings, an association, not a ranking.

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.