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Quiz Session - Attempts With Random Questions

ASE L3 Exam Questions

Page 1 of 10

1.

Technician A says wet compression tests can be performed on HEV vehicles. Technician B says there shouldn't be more than a five percent variation between cylinders. Which technician is correct?

  • Technician A

  • Both A and B

  • Technician B

  • Neither A nor B

Correct answer: Technician A

Technician A is correct. Conventional testing such as vacuum and wet/dry compression tests can be performed on HEV vehicles.

Technician B is incorrect. As a general rule, there should be no more than a 10 percent variation between the cylinders.

2.

Which of the following is TRUE regarding performing a compression test on a hybrid vehicle?

  • A scan tool must often be used to perform the test.

  • There should be no codes stored in the memory following the test.

  • There should be no unusual sounds indicating a mechanical problem during the test.

  • The inverter must be disconnected before performing the test.

Correct answer: A scan tool must often be used to perform the test.

On many hybrid vehicles, a scan tool must be used before performing a compression test. This is done to place the vehicle in a specific diagnostic mode.

The inverter doesn't need to be disconnected to perform a compression test. However, there could be strange sounds that indicate a mechanical problem, usually caused by the engine cranking over by MIG through a transmission torque damper. These sounds are considered normal. It's also normal to have codes stored in the system following the compression test. These codes can be cleared with a compatible scanner.

3.

The general procedure of compression testing an Atkinson engine is to

  • disable the fuel while having a lab scope connected to the battery.

  • disable the fuel while having a scan tool connected to the vehicle.

  • disable the spark while having a lab scope connected to the battery.

  • disable the spark while having the scan tool connected to the vehicle.

Correct answer: disable the fuel while having a lab scope connected to the battery.

Disabling the fuel while having a lab scope connected to the battery is the general procedure for compression testing an Atkinson cycle engine.

4.

Technician A says EV A/C systems are the same as conventional vehicle systems. Technician B says HV A/C systems require a stronger belt. Who is correct?

  • Neither A nor B 

  • Technician A 

  • Technician B

  • Both A and B

Correct answer: Neither A nor B

Both technicians are wrong. HV vehicles use an electric compressor, which makes them different from conventional systems, and they do not use a belt because they are electric.

5.

The Toyota Prius HEV has how many antifreeze reservoirs?

  • Two

  • One

  • Three

  • None

Correct answer: Two

Toyota uses two antifreeze reservoirs in the Prius HEV. The first one is for the power electronics cooling system and maintains the temperature with the inverter, transaxle fluid, and DC-DC converter. The second reservoir is for the engine cooling system.

6.

How many brushless types of MGs do PHEV vehicles use?

  • 2

  • 3

  • 1

  • 4

Correct answer: 2

There are two types of MGs PHEV vehicles use: AC synchronous permanent magnet and AC synchronous induction.  

7.

Technician A says that tap water is an acceptable option for mixing with coolant during a fluid change in an HEV. Technician B says the Chevrolet Volt PHEV has three independent cooling systems. Which technician is correct?

  • Technician B

  • Technician A

  • Both A and B

  • Neither A nor B

Correct answer: Technician B

Technician B is correct. The Chevrolet Volt PHEV contains three fully independent cooling systems. One is for the power electronics system, another for the battery pack, and a final one for the engine.

Technician A is incorrect. Tap water is conductive. When changing the coolant in an HEV, either use pre-mixed coolants or water that is de-ionized.

8.

Resolver signals are used to calculate all the following except:

  • The integrity of the stator

  • The rotational speed of the rotor

  • The rotational direction of the rotor

  • The physical position of the stator

Correct answer: The integrity of the stator

Resolver signals are used to detect three things: the rotational speed of the rotor, the direction of rotation of the rotor, and the physical position of the rotor.

9.

Technician A says inverters are a cylindrical shape and are dependent from other parts in the HV system. Technician B says inverters do not create enough heat for the need to cool them. Who is correct? 

  • Neither A nor B

  • Technician A

  • Technician B

  • Both A and B

Correct answer: Neither A nor B

Both technicians are wrong. Inverters come in many shapes and sizes. Inverters create a substantial amount of heat and need to be cooled.

10.

How many commonly used battery type cells are there?

  • Three

  • Four

  • Five

  • Two

Correct answer: Three

There are three commonly used types of cells: pouch, prismatic, and cylindrical.

11.

Technician A says there is an inspection plug located on top of the HV battery trays. Technician B says the inspection plug is used to check for internal leaks. Which technician is correct?

  • Technician B

  • Technician A

  • Both A and B

  • Neither A nor B

Correct answer: Technician B

Technician B is correct. The inspection plug is used to check for internal leaks.

Technician A is incorrect. There is an inspection plug, but it's located under the battery tray.

12.

Technician A says most smaller service disconnect plugs contain an HV fuse. Technician B says vehicles with large service disconnect levers have the HV fuse located inside of the battery housing. Who is correct?

  • Neither A nor B

  • Technician A

  • Technician B

  • Both A and B

Correct answer: Neither A nor B

Most large service disconnect levers contain the fuse internally. In most vehicles with small disconnects, the fuse is located within the battery tray.

13.

Technician A says some hybrid vehicles need a scan tool to bleed the cooling system. Technician B says vacuum pumps are sometimes needed to bleed hybrid vehicle cooling systems. Who is correct?

  • Both A and B

  • Technician A

  • Technician B

  • Neither technician A nor B

Correct answer: Both A and B

Scan tools and vacuum pumps are sometimes needed to perform a bleeding procedure for cooling systems.

14.

Technician A says the mat in an AGM battery is wrapped around the positive plate. Technician B says AGM batteries contain a one-way pressure relief valve. 

  • Both A and B

  • Technician A

  • Technician B

  • Neither A nor B

Correct answer: Both A and B

Both technicians are correct. The mat in an AGM battery is wrapped around the positive plate to protect from vibration. There is a one-way pressure valve to protect from thermal runaway.

15.

The HV electric A/C compressor typically has a built-in inverter that converts HV DC power to what?

  • Three-phase AC power

  • Single-phase AC power

  • Direct current power

  • Dual-phase AC power

Correct answer: Three-phase AC power

The three-phase AC power is needed to drive the small rotor that connects to the scroll compressor. Without this inverter, it wouldn't be possible to run the air conditioning system.

Direct Current (DC) power is what's being converted, while single- and dual-phase AC power have one or two active conductors instead of the three that are required.

16.

Technician A says under normal conditions, disabling the low voltage system will also disable the HV system. Technician B says high voltage cables are orange.

  • Both A and B

  • Technician A

  • Technician B

  • Neither A nor B

Correct answer: Both A and B

Both technicians are correct. On a normal operating HV with no faults, disabling the low voltage will also disable the HV system. The orange cables are for HV and can carry up to 800 volts.

17.

All the following are true regarding a compression test on an HEV Atkinson cycle ICE EXCEPT:

  • The specifications for relative compression testing are located in the vehicle owner's manual.

  • Performing a relative compression test on an Atkinson cycle HEV is a complicated procedure.

  • Some factory scan tools make relative compression testing available through the scan tool.

  • A lab scope can be used for relative compression testing an Atkinson cycle ICE engine.

Correct answer: The specifications for relative compression testing are located in the vehicle owner's manual.

The specifications for compression testing vehicles are located within the service manual, not the owner's manual.

18.

Technician A says a red triangle light on a Toyota may mean there's a headlight out. Technician B says that a Nissan with a warning light showing a vehicle and a double arrow below means there's a problem with the HV system. Which technician is correct?

  • Technician A

  • Both A and B

  • Technician B

  • Neither A nor B

Correct answer: Technician A

Technician A is correct. Toyota uses the red triangle light as the master warning light, so it could be a simple problem such as a headlight out, or something more serious.

Technician B is incorrect. Nissan has a light with a vehicle with a double arrow below it to show that the vehicle is ready to start or drive.

19.

During acceleration, what device produces three-phase HV AC power to drive the motors?

  •  The inverter

  • The high voltage contactor

  • The HV battery

  • The BECM

Correct answer: The inverter

The inverter produces a three-phase HV to drive the motors.

20.

A battery pack rated at 200 volts reads 180 volts on a scan tool. Technician A says the battery pack is faulty and should be replaced. Technician B says the battery pack should be rebuilt. Who is correct?

  • Neither A nor B

  • Technician A

  • Technician B

  • Both A and B

Correct answer: Neither A nor B

Both technicians are wrong. Battery voltage varies depending on state of charge. It's normal for a battery rated at 200 volts to measure 180 volts or 220 volts on a scan tool, depending on the state of charge. 

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