35 questions

General

An outside micrometer is used to measure:

  • a.Coolant temperature
  • b.Precise outside dimensions such as shaft or rotor thickness
  • c.Electrical resistance
  • d.Torque on a fastener

An outside micrometer measures external dimensions to a thousandth of an inch or finer, such as a rotor or crankshaft journal. The reading combines the sleeve and thimble scales. Proper technique and calibration are essential for accuracy.

General

A torque wrench is used to:

  • a.Measure bore diameter
  • b.Tighten fasteners to a specified value
  • c.Check tire tread depth
  • d.Test battery voltage

A torque wrench applies a controlled, specified amount of tightening force so fasteners are neither loose nor overtightened. Proper torque is critical for head bolts, wheels, and many other parts. The wrench should be set back to its lowest setting when stored to preserve calibration.

General

Technician A says wheel lug nuts can be tightened in any order. Technician B says they should be tightened in a crisscross (star) pattern to the specified torque. Who is correct?

  • a.Both A and B
  • b.Neither A nor B
  • c.Technician B only
  • d.Technician A only

Lug nuts must be tightened gradually in a crisscross pattern to seat the wheel evenly and prevent rotor distortion. Uneven or over-tightening can warp rotors and damage studs. Technician A is incorrect.

General

Technician A says a vehicle should be supported at the manufacturer's designated lift points. Technician B says rated jack stands should support a vehicle before working underneath it. Who is correct?

  • a.Both A and B
  • b.Technician A only
  • c.Technician B only
  • d.Neither A nor B

Vehicles must be supported at designated lift points and secured on rated jack stands, never held only by a hydraulic jack. Both technicians are correct. Following these practices prevents damage and serious injury.

General

Technician A says a dial indicator measures runout, endplay, and gear backlash. Technician B says it must be set up perpendicular to the surface for an accurate reading. Who is correct?

  • a.Both A and B
  • b.Neither A nor B
  • c.Technician B only
  • d.Technician A only

A dial indicator measures small linear movements such as rotor runout, crankshaft endplay, and backlash, and the plunger must contact the surface perpendicularly for accuracy. Both technicians are correct. It reads deflection in thousandths of an inch.

General

A vehicle's service information (repair manual) is the best source for:

  • a.Fuel prices
  • b.Torque specifications, procedures, and wiring diagrams
  • c.The owner's phone number
  • d.Weather forecasts

Service information provides the manufacturer's specifications, step-by-step procedures, wiring diagrams, and fluid capacities needed for correct repairs. Using accurate data prevents mistakes and comebacks. Technicians should verify specs rather than rely on memory.

General

If a bolt must be torqued to 90 foot-pounds and the specification then calls for an additional 90-degree turn, this method is known as:

  • a.Static balancing
  • b.Preloading only
  • c.Cross-torquing
  • d.Torque-to-yield (torque-plus-angle)

Torque-plus-angle (torque-to-yield) tightens the fastener to a base torque and then a specified angle, stretching it for consistent clamp load. It is common on head bolts and other critical fasteners. A torque-angle gauge or electronic tool measures the additional rotation.

General

Proper personal protective equipment when grinding or working with the battery includes:

  • a.Only gloves
  • b.Only a hat
  • c.Eye protection and appropriate gloves
  • d.No protection needed

Eye protection guards against flying particles and battery acid, and gloves protect the hands from sharp edges and corrosive chemicals. Battery work also warrants care because of explosive hydrogen gas and acid. Safety equipment reduces the risk of injury.

General

Converting a measurement, a technician knows there are 25.4 millimeters in one inch. A 2-inch dimension equals approximately:

  • a.50.8 mm
  • b.254 mm
  • c.12.7 mm
  • d.2.54 mm

Multiplying 2 inches by 25.4 mm/inch gives 50.8 millimeters. Being comfortable converting between metric and standard units is important because vehicles use both. Measuring tools and specifications may be given in either system.

General

A feeler gauge is used to measure:

  • a.The gap or clearance between two parts
  • b.Tire pressure
  • c.Electrical current
  • d.Engine vacuum

A feeler gauge consists of thin metal blades of known thickness used to measure small gaps, such as valve lash or spark plug gap. The correct blade slides through the gap with a slight drag. It is a simple but precise clearance-measuring tool.

General

A vernier or dial caliper is commonly used to measure:

  • a.inside, outside, and depth dimensions to about a thousandth of an inch
  • b.the electrical resistance measured across a wiring connector
  • c.the amount of torque that has been applied to a fastener
  • d.only the outside diameter of round shafts and nothing else

A caliper measures outside, inside, and depth dimensions and reads to roughly 0.001 inch (or 0.02 mm), making it versatile for many measurements. It is less precise than an outside micrometer for critical diameters. Proper technique avoids rocking the jaws for an accurate reading.

General

A thread pitch gauge is used to determine a fastener's:

  • a.overall length measured under the head of the fastener
  • b.torque-to-yield final tightening specification
  • c.hardness or strength grade of the fastener's steel
  • d.number of threads per inch or thread pitch

A thread pitch gauge has blades matching common thread counts; the blade that fits the threads identifies the pitch or threads per inch. This helps select the correct nut, bolt, or tap. Matching pitch prevents cross-threading and stripped fasteners.

General

Converting torque units, 1 foot-pound is equal to:

  • a.1.36 inch-pounds, mixing up newton-meters with inches
  • b.100 inch-pounds, confusing feet with a larger unit
  • c.12 inch-pounds
  • d.10 inch-pounds, using a rounded conversion factor

Because a foot is 12 inches, one foot-pound equals 12 inch-pounds of torque. A specification of 60 inch-pounds is therefore 5 foot-pounds. Using the correct unit prevents badly over- or under-tightened fasteners on small components.

General

A common and recommended practice for a click-type torque wrench is to:

  • a.store it fully tightened in order to keep it accurate
  • b.back the setting down to its lowest value for storage
  • c.use it as a breaker bar to loosen tight, seized fasteners
  • d.leave it set at its maximum torque value between uses

Relaxing the spring by dialing the wrench down to its lowest setting for storage helps preserve calibration. A torque wrench should not be used to loosen fasteners or as a breaker bar, which can damage it. Periodic recalibration keeps readings accurate.

General

On an SAE bolt head, radial lines (slashes) stamped on the head indicate the:

  • a.country in which the fastener was manufactured
  • b.overall length of the bolt shank beneath the head
  • c.thread pitch, or threads per inch, of the bolt
  • d.strength grade of the fastener

SAE bolt grades are marked with radial lines; a grade 5 bolt has three lines and a grade 8 has six, indicating higher strength. Metric bolts use a numeric class such as 8.8 or 10.9. Replacing a bolt with a lower grade than specified can cause failure.

General

A thread-repair insert (such as a Heli-Coil) is used to:

  • a.increase a bolt's outside diameter permanently in the part
  • b.restore stripped internal threads to the original size
  • c.measure the depth of a drilled or tapped bolt hole
  • d.harden a soft fastener after it has been installed

A coil or solid insert is installed into a re-tapped hole to rebuild damaged internal threads back to the original bolt size, avoiding replacement of the whole part. It is common in aluminum components like cylinder heads. Correct drill, tap, and insert length must be used.

General

The correct type of fire extinguisher for a gasoline or oil (flammable liquid) fire is a class:

  • a.K extinguisher
  • b.D extinguisher
  • c.B extinguisher
  • d.A extinguisher

Class B extinguishers are rated for flammable liquids like gasoline and oil, while class A is for ordinary combustibles and class C for energized electrical fires. Many shop extinguishers are rated B and C together. Using the wrong type can spread a liquid fire.

General

A Safety Data Sheet (SDS) provides a technician with information about:

  • a.the wiring diagram and pin-out for a specific vehicle circuit
  • b.the alignment angles such as camber and toe for the suspension
  • c.the torque specifications for tightening the engine's fasteners
  • d.the hazards, handling, and first aid for a chemical product

An SDS details a product's hazards, safe handling, protective equipment, and emergency and first-aid measures. Employers must keep these accessible for shop chemicals. Reading the SDS before use protects the technician and coworkers.

General

Running an engine indoors requires connecting the exhaust to a ventilation system primarily because:

  • a.it prevents the vehicle's battery from being overcharged
  • b.exhaust contains carbon monoxide, a colorless, odorless, deadly gas
  • c.venting improves the accuracy of the wheel alignment machine
  • d.the exhaust would otherwise cool the engine down far too quickly

Carbon monoxide in exhaust is toxic and cannot be seen or smelled, so an exhaust extraction system must vent it outside. Even brief exposure in an enclosed shop is dangerous. Ventilation is a basic and required shop safety practice.

General

Before working around a deployed-capable airbag (SRS) system, the technician should generally:

  • a.carry a live airbag module face-down and pointed toward the body
  • b.leave the battery connected so the system keeps full power
  • c.strike the airbag module firmly to test that it still responds
  • d.disconnect the battery and wait the specified time before servicing

Disconnecting the battery and waiting the manufacturer-specified time lets the SRS capacitor discharge so the airbag cannot deploy accidentally during service. A live module should be carried facing away from the body and set face-up. Always follow the service manual's SRS precautions.

General

When lifting a heavy object such as a transmission by hand, a technician should:

  • a.hold the load out far away from the body while lifting
  • b.lift with the legs while keeping the back straight
  • c.bend at the waist and lift using the muscles of the back
  • d.twist the torso to one side while raising the heavy load

Lifting with the leg muscles and a straight back, keeping the load close, reduces the risk of back injury. Bending and twisting at the waist strains the spine. For very heavy items, a hoist or a coworker's help should be used.

General

An impact wrench should generally NOT be used for final tightening of wheel lug nuts because it:

  • a.cannot loosen rusted or seized lug nuts on the wheel at all
  • b.turns the fasteners too slowly to seat the wheel properly
  • c.produces no useful rotational force on the lug nuts
  • d.can over-torque the fasteners and warp brake rotors

An impact wrench can apply uneven, excessive torque that stretches studs and distorts rotors, so lug nuts should be final-tightened with a torque wrench in a star pattern. Torque sticks help limit force but are not a substitute for verifying with a torque wrench. Proper torque prevents warping and loosening.

General

A left-hand thread fastener is designed so that it:

  • a.uses a much finer thread pitch than a right-hand thread
  • b.loosens when turned clockwise and tightens counterclockwise
  • c.requires no torque specification at all when it is tightened
  • d.cannot ever be removed once it has been installed

Left-hand threads reverse the normal direction, tightening counterclockwise, and are used where normal rotation would tend to loosen a fastener, such as some spindle nuts or blade bolts. Recognizing them prevents damage from forcing them the wrong way. They are often marked with an 'L' or grooves.

General

A bench grinder's tool rest should be adjusted so the gap between the rest and the wheel is:

  • a.small, about one-sixteenth of an inch, to keep work from being pulled in
  • b.exactly one full inch, which is considered the safe distance
  • c.as large as possible in order to give plenty of clearance
  • d.irrelevant, because the gap does not affect safe operation

Keeping the tool rest within about 1/16 inch of the wheel prevents the workpiece from catching and being drawn between the rest and the wheel. Eye protection and inspecting the wheel for cracks are also essential. Never grind on the side of a straight wheel.

General

A castle (castellated) nut is used with a cotter pin to:

  • a.positively lock the nut so it cannot back off
  • b.increase the clamping torque well beyond the specification
  • c.measure the amount of endplay present in the assembly
  • d.seal fluid inside a threaded fitting to prevent a leak

The slots in a castle nut align with a hole in the fastener so a cotter pin holds the nut from rotating loose, common on tie-rod ends and spindle nuts. A new cotter pin should be used on reassembly. This is a mechanical locking method for safety-critical fasteners.

General

The vehicle identification number (VIN) is important to a technician because it:

  • a.lists the previous owner's name and contact details
  • b.shows the current amount of fuel remaining in the tank
  • c.identifies the exact vehicle for correct parts and service info
  • d.records only the vehicle's tire-pressure specification

The 17-character VIN encodes the make, model, engine, and other build details needed to look up the right parts, specifications, and procedures. It is found on the dash, door jamb, and registration. Ordering parts by VIN avoids costly mismatches.

General

A technical service bulletin (TSB) issued by a manufacturer provides:

  • a.guidance and updated procedures for known, recurring problems
  • b.the vehicle's original window-sticker selling price
  • c.a specific customer's personal maintenance history
  • d.a legally mandated safety recall notice sent to the owner

A TSB documents a known issue and the recommended repair or updated procedure to help technicians fix recurring problems efficiently. Unlike a recall, a TSB is not a mandatory safety campaign. Checking TSBs early can save diagnostic time.

General

Penetrating oil is applied to a rusted, seized fastener in order to:

  • a.measure how deep the corrosion has gone into the metal
  • b.weld the fastener permanently into place in the threads
  • c.seep into the threads and ease removal
  • d.increase the torque rating that the fastener can withstand

Penetrating oil works into corroded threads to reduce friction so a stuck fastener can be loosened with less risk of breaking it. Allowing it time to soak improves results. Heat may also be used carefully to help free badly seized fasteners.

General

A dial or digital micrometer typically offers greater precision than a caliper, reading to about:

  • a.one full centimeter
  • b.one ten-thousandth of an inch on some models
  • c.one full inch, far coarser than any precision tool would give
  • d.one-eighth of an inch

A micrometer measures to 0.001 inch, and vernier or digital versions resolve to 0.0001 inch, making it the tool for critical diameters like crankshaft journals. A caliper, by contrast, reads to about 0.001 inch. Proper feel and calibration ensure an accurate micrometer reading.

General

When jacking up a vehicle, the technician must place the jack and stands at:

  • a.the manufacturer's designated lift points
  • b.the plastic bumper covers at the front or the rear
  • c.any flat spot found on the vehicle's sheet-metal floor pan
  • d.the middle section of the exhaust pipe under the vehicle

Factory lift points are reinforced to bear the vehicle's weight safely; jacking on unapproved spots can crush panels or cause the vehicle to fall. Rated jack stands must support the vehicle before anyone works underneath. The service manual shows the correct locations.

General

A dial bore gauge is used to measure:

  • a.the outside diameter of a crankshaft main or rod journal
  • b.the inside diameter, taper, and out-of-round of a cylinder bore
  • c.the amount of torque that has been applied to a head bolt
  • d.the electrical resistance of a sensor's signal circuit

A dial bore gauge measures internal diameter accurately at several depths, revealing taper and out-of-round in cylinders or bores. It must be set to size with a micrometer or ring first. Readings guide the decision to bore or hone a cylinder.

General

Compressed air used for cleaning should be handled carefully because:

  • a.it improves a person's eyesight when it is aimed at the face
  • b.it is completely harmless to a person at any pressure level
  • c.it must be inhaled in order to check the air's quality
  • d.high-pressure air can inject debris into skin or eyes and injure

High-pressure air can drive dirt and particles into the skin or eyes and should never be aimed at oneself or others; eye protection is required. Regulators limit pressure for cleaning tasks. Following shop safety rules prevents serious injury.

General

Used engine oil, coolant, and similar fluids must be:

  • a.dumped onto the bare ground behind the repair shop
  • b.poured directly down the shop floor drain to get rid of it
  • c.collected and disposed of or recycled according to regulations
  • d.mixed together and then burned off out in the open air

Waste automotive fluids are regulated and must be captured and sent for proper recycling or disposal to protect the environment and comply with law. Mixing incompatible fluids can prevent recycling. Shops keep labeled containers for each waste type.

General

Recovering and recycling A/C refrigerant during service is required because:

  • a.refrigerant is completely safe to release once the engine is off
  • b.recovery is done in order to lower the vehicle's tire pressure
  • c.it is only a manufacturer suggestion rather than a legal rule
  • d.venting refrigerant to the atmosphere is illegal and harmful

Refrigerant must be recovered with proper equipment rather than vented, both to comply with environmental law and to protect the atmosphere. Technicians handling refrigerant require the appropriate certification. Recovered refrigerant can be recycled and reused.

General

Standard shop practice for starting fasteners on a critical assembly is to:

  • a.use maximum impact-gun power to seat them all as quickly as possible
  • b.tighten only the outer fasteners and skip the center ones
  • c.start all fasteners by hand before final tightening to avoid cross-threading
  • d.run each fastener straight to full torque one at a time immediately

Starting threads by hand ensures they engage correctly and are not cross-threaded before power tools or final torque are applied. Many assemblies are then torqued in a specified sequence and multiple steps. This prevents leaks, distortion, and stripped threads.

这门考试有多难?

ASE 汽车认证由八门独立考试组成(A1-A8)。每门初考有 40-50 道计分题(另加 10 道不计分的研究题),时长 60-90 分钟;费用为每次报名 34 美元加每门考试 62 美元。ASE 采用标准参照的换算分,不公布通过百分比。汽车维修技师与机修工年薪中位数约 49,670 美元(BLS,2024 年 5 月)。

推荐学习时间
多数人每门 20-40 小时,另加取得完整认证所需的动手工作经验。
通过率
我们在 2026 年 9 月查阅了 ASE 自己公布的材料,其中没有通过率。ase.com 没有统计页面 —— 看起来像统计页的网址会跳转到关于我们页 —— A1-A9 的考试页面和 FAQ 也都没有通过率。每科采用由专家小组设定的效标参照及格分,因此没有可报告的分布曲线。来源: ASE — FAQs and Test Results · ASE — Automobile tests A1-A9
重点学习方向
因考试而异——例如一般发动机诊断占 A1(发动机维修)的 40%,计算机化发动机控制占 A8(发动机性能)的 26%。

费用与薪资为近似值,会随时间变动。上方的通过率引自旁边链接的来源,并限于该来源覆盖的期间——凡是我们尚未核实来源的,都会直接说明并且不给数字。

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