100+ Free ASE H2 Diesel Engines (Transit Bus) Practice Questions
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Insufficient (too tight) valve clearance on a diesel engine is most likely to cause:
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Key Facts: ASE H2 Diesel Engines (Transit Bus) Exam
60
Total Questions (50 Scored)
ASE Transit Bus test series
75 min
Testing Time
ASE Transit Bus test series
~$59
ASE Test Registration
ASE registration
Criterion-referenced
Scoring Standard
ASE scoring policy
2 years
Required Work Experience
ASE certification requirements
28 / 22 / 14
Top Three Content-Area Weights
ASE Transit Bus H2 content outline
ASE H2 — Diesel Engines (Transit Bus) is a 60-question test with 50 scored multiple-choice items and a 75-minute time limit, delivered by appointment through Prometric. ASE uses criterion-referenced scoring, so the passing standard is set by ASE rather than a fixed percentage, and certification requires two years of relevant work experience (training can substitute for part of it). The official content weighting is General Engine Diagnosis 28%, Cylinder Head & Valve Train 8%, Engine Block 8%, Lubrication & Cooling 14%, Air Induction & Exhaust 12%, Fuel System 22%, and Starting & Charging 8%.
Sample ASE H2 Diesel Engines (Transit Bus) Practice Questions
Try these sample questions to test your ASE H2 Diesel Engines (Transit Bus) exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1A transit bus diesel engine cranks normally but will not start, and there is no smoke from the exhaust during cranking. Which condition is the most likely cause?
2Technician A says low engine power on a transit bus can be caused by a restricted air filter. Technician B says it can be caused by a plugged diesel particulate filter (DPF). Who is correct?
3During a manual cylinder cutout (cylinder contribution) test on a Cummins ISL, one cylinder produces no change in engine rpm when its injector is disabled. This indicates that the cylinder is:
4A transit bus diesel produces continuous black smoke under acceleration. Which of these is the most likely cause?
5Blue-gray smoke from a transit bus diesel exhaust, especially at startup and during deceleration, most likely indicates:
6Persistent white smoke from a warmed-up transit bus diesel, accompanied by a gradually dropping coolant level and a sweet odor, most strongly points to:
7An engine oil sample analysis from a transit bus shows a high level of coolant (glycol) and elevated sodium/potassium. The most likely cause is:
8A transit bus diesel has low power and the ECM logs a fault for low boost pressure. The least likely cause of this fault is:
9When performing a cylinder compression test on a transit bus diesel, the most accurate procedure is to:
10A transit bus diesel has a steady knocking noise that increases with engine speed and is loudest under load. This is most consistent with:
About the ASE H2 Diesel Engines (Transit Bus) Exam
ASE H2 is the Diesel Engines test in the ASE Transit Bus (H Series) certification program for technicians who service transit-bus diesel power. The test covers general engine diagnosis, cylinder head and valve train, engine block, lubrication and cooling, air induction and exhaust, fuel systems, and starting and charging, with the heaviest emphasis on diagnosis and fuel systems.
Assessment
50 scored multiple-choice (60 total incl. 10 unscored) (official ASE); this practice bank is 100 selected-response items
Time Limit
75 minutes
Passing Score
Criterion-referenced (set by ASE)
Exam Fee
~$59 (ASE registration) (ASE (National Institute for Automotive Service Excellence))
ASE H2 Diesel Engines (Transit Bus) Exam Content Outline
General Engine Diagnosis
Low power, hard start, no-start, smoke color analysis, abnormal noise, blow-by, oil and coolant analysis, cylinder cutout/contribution testing, engine derates, and transit severe-service duty-cycle effects.
Cylinder Head & Valve Train Diagnosis & Repair
Valve lash effects, valve guides and stem seals, burned valves, valve springs and float, head warpage and flatness, head gasket sealing, and torque-to-yield head fastener procedures.
Engine Block Diagnosis, Repair & Overhaul
Cylinder bore taper and out-of-round, liner protrusion, bearing clearance with Plastigage, crankshaft end play, main bore alignment, cylinder honing, and piston/block damage analysis.
Lubrication & Cooling Systems Diagnosis & Repair
Oil pressure diagnosis, oil analysis interpretation, oil cooler failures, thermostats, cooling fan and fan drive, pressure cap, supplemental coolant additive, liner cavitation, and internal-leak testing.
Air Induction & Exhaust Systems Diagnosis & Repair
Air intake restriction, charge-air cooler leaks, turbocharger and VGT operation, EGR cooler failures, exhaust backpressure, and DPF/SCR/DEF aftertreatment and regeneration diagnosis.
Fuel System Diagnosis & Repair
Low-pressure supply and lift pumps, common-rail and unit injectors, rail pressure and high-pressure pump, injector return/leak-off and calibration coding, fuel contamination, ULSD, and high-pressure safety.
Starting & Charging System Diagnosis & Repair
Battery bank and cranking diagnosis, voltage-drop testing, starter control circuit and interlocks, alternator output and AC ripple, charging-system regulation, and overcharge conditions.
How to Pass the ASE H2 Diesel Engines (Transit Bus) Exam
What You Need to Know
- Passing score: Criterion-referenced (set by ASE)
- Assessment: 50 scored multiple-choice (60 total incl. 10 unscored) (official ASE); this practice bank is 100 selected-response items
- Time limit: 75 minutes
- Exam fee: ~$59 (ASE registration)
Keys to Passing
- Complete 500+ practice questions
- Score 80%+ consistently before scheduling
- Focus on highest-weighted sections
- Use our AI tutor for tough concepts
ASE H2 Diesel Engines (Transit Bus) Study Tips from Top Performers
Frequently Asked Questions
How many questions are on the ASE H2 test?
The official ASE H2 Transit Bus Diesel Engines test has 60 questions, of which 50 are scored multiple-choice items and 10 are unscored research questions that do not affect your result. This free practice bank provides 100 selected-response questions distributed across the same seven official content areas.
How long do I get for the ASE H2 exam?
ASE allows 75 minutes for the H2 test. Because only 50 questions are scored, pacing is manageable, but transit-bus diesel diagnosis questions can be scenario-based, so practice reading carefully and reasoning through symptoms quickly.
What passing score do I need on ASE H2?
ASE uses criterion-referenced scoring, so there is no fixed percentage you must hit. The passing standard is set by ASE based on the knowledge required to perform the work, and your score report shows whether you met that standard along with performance by content area.
What are the experience requirements for ASE H2 certification?
ASE certification requires two years of relevant hands-on work experience. Relevant formal training can substitute for up to one of those years. You can take the test before completing the experience, but certification is granted once both the passing score and the experience requirement are met.
What content is weighted most heavily on ASE H2?
General Engine Diagnosis is the largest area at 28%, followed by Fuel System at 22% and Lubrication & Cooling at 14%. Air Induction & Exhaust is 12%, while Cylinder Head & Valve Train, Engine Block, and Starting & Charging are 8% each, so weight your study toward diagnosis and fuel systems.
Where and how is the ASE H2 test delivered?
ASE tests, including H2, are delivered by appointment at Prometric test centers. You register through ASE, schedule a Prometric appointment, and take the computer-based test. Confirm current scheduling and recertification details in your ASE account before registering.