Resume Guide
Diesel Mechanic Resume: What Hiring Managers Actually Look For
By the ApplyDocket team
Most online advice for diesel mechanic resumes is written by people who have never set foot in a shop. They tell you to "demonstrate problem-solving skills" and "highlight teamwork." Fleet managers and shop foremen are not reading your resume for that. They want to know which engine platforms you have turned wrenches on, which diagnostic tools you can run, and whether your certifications are current.
This page covers what to put on a diesel mechanic resume, how to write experience bullets that mean something, and what every working diesel tech needs to know about listing ASE certs.
Diesel Mechanic Resume Example
The example below uses real engine platforms, real diagnostic tools, and real certification designations. That specificity is the point. A resume that says "repaired diesel engines" is not useful to anyone reviewing it. A resume that says "PACCAR MX-13 and Cummins X15, diagnosed with Cummins Insite and Nexiq USB-Link 2" tells a fleet manager something.
Marcus Webb
Diesel Technician
Boise, ID | marcus.webb@email.com | (208) 555-0147
SUMMARY
Diesel technician with 9 years maintaining and repairing Class 6-8 commercial vehicles. Experienced with Cummins ISX/X15, Detroit DD15, and PACCAR MX-13 platforms. Proficient in Cummins Insite, Detroit Diagnostic Link, and Nexiq USB-Link 2. EPA-compliant DPF/EGR/DEF diagnostics and repair. DOT-certified annual vehicle inspector.
LICENSES & CERTIFICATIONS
EXPERIENCE
EQUIPMENT & TOOLS
Cummins ISX/X15/ISB, Detroit DD13/DD15/DD16, PACCAR MX-13/MX-11, CAT C13/C15, Cummins Insite, Detroit Diagnostic Link, Nexiq USB-Link 2, Jaltest, Eaton Fuller RTX series, Allison 3000/4000 series
SKILLS
DPF/EGR/DEF diagnostics, EGR valve/cooler repair, DEF/SCR systems, forced regen procedures, air brake systems, ABS diagnostics, DOT annual inspection, PM scheduling, MIG/stick welding
EDUCATION
College of Southern Idaho Twin Falls, ID A.A.S. Automotive & Diesel Technology 2015
Sample resume for illustration. Names and contact details are fictional.
ASE Certifications: What to List and How
The ASE Medium/Heavy Truck certification series runs T1 through T8. Each covers a specific system:
- T1Gasoline Engines
- T2Diesel Engines
- T3Drive Train
- T4Brakes
- T5Suspension and Steering
- T6Electrical/Electronic Systems
- T7Heating, Ventilation, and Air Conditioning
- T8Preventive Maintenance Inspection
Hold all eight and you qualify for the ASE Master Medium/Heavy Truck Technician designation. List it explicitly as "ASE Master Medium/Heavy Truck Technician," not just "ASE Certified." Many technicians hold T2 (Diesel Engines) and T4 (Brakes) but not the full set; list what you actually have.
The FMCSA air brake certification (49 CFR 396.25) is required to inspect air brake systems. If you have it, list it. Many shops that run DOT-regulated fleets require it and will filter for it.
OEM training certifications (Cummins Level I/II, Detroit Certified Technician, PACCAR dealer training) are worth listing separately. They signal that you can run manufacturer diagnostic software and coordinate warranty repairs through the OEM network.
What to Put in Your Skills Section
Group your skills by category. A flat list of 20 items is hard to read; a categorized list lets the reviewer find what they need in 10 seconds.
Engine Platforms
List the specific platforms you have hands-on experience with. Generic entries like "diesel engines" tell a hiring manager nothing.
Examples: Cummins ISX, X15, ISB 6.7 / Detroit DD13, DD15, DD16 / PACCAR MX-13, MX-11 / CAT C13, C15, C7 / International Navistar A26, N13
Diagnostic Tools
Name the specific software and hardware you use. "Diagnostic equipment" is not useful. The software names are.
Examples: Cummins Insite / Detroit Diagnostic Link (DDL) / Nexiq USB-Link 2 / Jaltest / ServiceMaxx (International) / JPRO Fleet Diagnostics / Autel MaxiSys Heavy Duty
Emissions and Aftertreatment
DPF/EGR/DEF experience is increasingly important as EPA Tier 4 and GHG regulations have put aftertreatment systems on nearly every late-model diesel. Be specific about what you can diagnose and repair.
Examples: DPF cleaning and replacement / EGR valve and cooler repair / DEF injector service / SCR catalyst replacement / forced regeneration procedures / diesel oxidation catalyst (DOC) service
Transmissions and Drivetrain
Examples: Eaton Fuller RTX-15610B, RTLO-18918B / Allison 3000 Series, 4000 Series / Meritor rear axles / Dana Spicer driveshafts / transfer cases
How to Write Experience Bullets That Work
The difference between a weak bullet and a strong one is specificity. Here are direct comparisons:
Repaired diesel engines and maintained fleet vehicles
Diagnosed and repaired Cummins X15 engine failures including EGR cooler replacements and injector sleeve leaks on a 34-truck OTR fleet
Used diagnostic equipment to identify problems
Used Cummins Insite and Nexiq USB-Link 2 to diagnose aftertreatment faults; reduced DPF forced regen events by 30% through scheduled desoot intervals
Performed preventive maintenance on schedule
Maintained A/B/C PM intervals for 47 Class 8 tractors per OEM schedule; sustained 97% fleet availability over 18 months
Worked on transmissions
Rebuilt Allison 3000 Series automatic transmissions and replaced Eaton Fuller RTX-14609 clutch packs on Class 6 delivery trucks
Common Mistakes on Diesel Mechanic Resumes
Burying or omitting certifications
ASE certs and your FMCSA air brake certification belong near the top of your resume, not at the bottom of a skills list. Many shops filter for these before reading anything else. If you have the Master Medium/Heavy Truck designation, put it in your header or right below your name.
Using the wrong tone
Office-worker language sounds wrong on a trades resume. 'Managed maintenance operations and leveraged cross-functional collaboration' is not how a shop foreman thinks about the job. 'Ran PM schedules for a 40-truck fleet, coordinated with parts suppliers, handled warranty claims directly with Cummins' says the same thing in language that fits.
Listing certifications without designations
'ASE Certified' is not enough. T2 and T4 are different from T1 and T6. List each designation individually so the reviewer knows exactly which systems you have been tested on.
Vague equipment entries
Writing 'diesel trucks' or 'commercial vehicles' when you mean 'Class 8 OTR tractors running Cummins X15 and Detroit DD15 engines' wastes a line. The specific platform is the information. The category heading is not.
Not mentioning software
A technician who can run Cummins Insite and read PIDs off a real dataset is more useful to a fleet shop than one who can only work from symptom descriptions. If you can run the OEM diagnostic software, put it on your resume.
Common Questions
Should I list all eight T-series certifications individually?
Yes, if space allows. If you hold the Master Medium/Heavy Truck designation, list that first, then list the individual T-certs below it. Some job postings specify particular T-certs (T4 for brake specialist roles, T6 for electrical/diagnostic work). Listing them individually makes it easy for a reviewer to confirm you have what the role requires.
How do I list OEM-specific training on a resume?
Give it a separate line under certifications. 'Cummins Diesel Engine Training, Level I and II' and 'Detroit Certified Technician for the DD15 platform' are worth listing explicitly. These signal that you can use manufacturer diagnostic tools and coordinate warranty repairs with the OEM dealer network, which matters to fleet shops that run mixed equipment.
I have experience with older engine platforms (pre-emissions). Should I still list them?
Yes. Pre-emission Cat C15s and older Detroit Series 60s are still running in vocational and agricultural fleets. Shops that service older equipment actively look for technicians with mechanical injection experience. List older platforms separately so they are visible. 'Legacy platforms: CAT 3406E, C15 Acert, Detroit Series 60' works fine.
Do I need a CDL to get hired as a diesel mechanic?
Not always, but many fleet shops and dealerships prefer technicians who can move vehicles for road testing and delivery. If you have a CDL Class A, list it. If you have a Class B, list that. It removes a logistics problem for the employer.
ApplyDocket
Tailor your diesel mechanic resume to each job posting
A diesel mechanic job at a Kenworth dealership is not the same as a fleet position at a regional carrier or a service technician role at a rental equipment company. The equipment differs, the diagnostic tools differ, and the language on the job posting differs.
ApplyDocket reads the actual job posting and rewrites your resume around it, surfacing the keywords and credentials the employer listed where your experience supports them. If the posting says "Cummins ISX" and you have it, your resume will say "Cummins ISX." If it says "Nexiq," your resume will say "Nexiq." That takes 30 minutes per application to do manually. ApplyDocket does it in about 5.
The Skilled Pro template was built specifically for trades workers and first responders, with dedicated fields for certifications, licenses, and equipment, formatted so credentials are visible, not buried in a generic skills section.
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