Heavy-Duty Diesel Mechanic: Diagnostics & Emissions

SET Environmental Inc; Wheeling (IL); On-site; USD 55,000 - 75,000; Full time

Job summary

SET Environmental Inc. seeks an experienced Diesel Mechanic to perform preventive maintenance, diagnose and repair heavy‑duty diesel trucks, and service emissions systems in our workshop.

You will handle electrical, hydraulic, and PTO components, follow OEM procedures, and document repairs with detailed work orders. The role requires 3+ years of diesel experience, CDL/A or ability to obtain, and a strong safety mindset.

Qualifications

• 3+ years diagnosing and repairing heavy‑duty diesel trucks and related systems.
• Ability to read wiring diagrams and use diagnostic software and electrical test equipment.
• CDL-A or CDL, or ability to obtain; DOT physical and valid DOT medical card required.
• ASME-BASE medium/heavy truck certifications or equivalent experience preferred.
• OEM diagnostic experience and hydraulic/PTO experience preferred.

Responsibilities

• Perform preventive maintenance and inspect heavy vehicles for defects.
• Diagnose and repair diesel engines, fuel, cooling, starting, charging, and electrical systems.
• Diagnose diesel emissions faults (DPF, SCR, DEF) and complete repairs per procedures.
• Inspect and repair brakes, air systems, steering, suspension, driveline, and trailers.
• Troubleshoot and maintain hydraulic systems, PTOs, and auxiliary equipment.
• Create work orders with findings, parts, and labor; verify repairs with tests.
• Maintain shop safety, cleanliness, and timely communication of repair status.

Skills

Reading wiring diagrams

Diagnostic software usage

Electrical test equipment

Team collaboration

Education

High School Diploma or equivalent

ASME-BASE medium/heavy truck certifications or equivalent

Tools

Diagnostic tools

OEM service procedures manuals

Job description

SET Environmental Inc. seeks an experienced Diesel Mechanic to perform preventive maintenance, diagnose and repair heavy‑duty diesel trucks, and service emissions systems in our workshop.

You will handle electrical, hydraulic, and PTO components, follow OEM procedures, and document repairs with detailed work orders. The role requires 3+ years of diesel experience, CDL/A or ability to obtain, and a strong safety mindset.