The National Institute for Automotive Service Excellence (ASE) offers T-Series and E-Series certification tests that verify the proficiency of professional service technicians who work on medium-heavy trucks and equipment.

Designed to identify and recognize medium and heavy truck technicians who demonstrate knowledge of the skills necessary to diagnose, service, and repair different systems of Class 4 through Class 8 trucks and tractors, ASE offers eight T-Series certification tests. The tests include gasoline engines (T1); diesel engines (T2); drive train (T3); brakes (T4); suspension and steering (T5); electrical/electronic systems (T6); heating, ventilation and air conditioning (HVAC) (T7); and preventive maintenance inspection (T8). Those who are certified in tests T2–T8 are recognized as ASE Certified Master medium-heavy truck technicians.

The ASE truck equipment E-Series certification tests are designed to identify and recognize those truck equipment technicians who can demonstrate knowledge of the skills necessary to install, diagnose, service, and repair truck equipment and related support systems on all classes of trucks and tractors. Three tests are offered including truck equipment installation and repair (E1), electrical/electronic systems installation and repair (E2), and auxiliary power systems installation and repair (E3). Those who are certified in tests E1–E3 are recognized as ASE-Certified Master truck equipment technicians.