ASE T2 Diesel Engines practice test
The T2 test is the heart of the truck series — 55 scored questions on diesel diagnosis, fuel systems, turbocharging, and the aftertreatment stack (DPF, EGR, SCR/DEF) that dominates modern diesel work. Required for Master Truck status.
A tractor overheats only on slow, heavy pulls with high engine load at low road speed. The radiator is clean and the coolant level correct. Technician A says a fan clutch that never engages could be the cause. Technician B says an air-actuated fan clutch can be command-tested with the scan tool or by its control circuit. Who is correct?
How the T2 test works
55 scored questions
+ ~10 unscored research questions
90 minutes
computer-based, at a test center
$62 per test
plus one $34 registration fee per order
Valid 5 years
then a shorter recertification test
ASE does not publish a fixed passing percentage — scores are scaled. Around 65–70% correct is the commonly cited range; aim above 80% in practice so you walk in with margin. The certificate is issued once ASE verifies your required work experience.
What the T2 test covers
The official task list for T2 Diesel Engines (Medium-Heavy Truck) breaks down into these content areas — the practice bank above draws from all of them:
- General diesel diagnosis — hard start, low power, smoke color, noise, crankcase pressure
- Cylinder head and valve train — including overhead adjustment
- Engine block, lubrication, and cooling systems
- Air induction and exhaust — turbochargers, charge air coolers, restrictions
- Fuel systems — supply, filtration, water separation, and high-pressure injection
- Emissions and aftertreatment — EGR, DPF regeneration, SCR/DEF, sensors
Frequently asked
- How many questions are on the ASE T2 test?
- The T2 test has 55 scored questions plus about 10 unscored research questions, with a 90-minute time limit — the largest T-series test.
- Is T2 required for Master Truck status?
- Yes. Master Medium-Heavy Truck Technician status requires passing T2 through T8.
- What should I focus on for T2?
- Aftertreatment logic (DPF regen strategies, SCR/DEF faults) and air-side diagnosis (turbo, charge air cooler, restrictions) — modern trucks generate most diesel work in exactly those systems.
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