ASE xEV (Level 2) Exam Questions

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81.

What refrigerant oil should be used with xEVs?

  • Original Equipment Manufacturer (OEM) recommendations

  • PAG 46

  • PAG 150

  • PAG 100

Correct answer: Original Equipment Manufacturer (OEM) recommendations

The only refrigerant oil used should be the non-conductive type recommended by the Original Equipment Manufacturer (OEM). Reference the OEM specs or reach out to the manufacturer for more guidance.

PAG (Polyalkylene Glycol) oil should never be used because it is hygroscopic. 

82.

How can power be cut off at the source of electric shock if it's coming from an electrified vehicle?

  • Manual Service Disconnect (MSD)

  • Fuse

  • Relay

  • Charging cord

Correct answer: Manual Service Disconnect (MSD)

The Manual Service Disconnect (MSD) lever is a low-voltage component that removes power from the contractor control circuits. By removing the MSD, the system becomes de-energized.

If the source of the power is coming from the high-voltage battery, there may not be a disconnect available. 

83.

Technician A believes that an insulation inspection must be performed visually before reconnecting a high-voltage battery. Technician B says that an insulation testing tool must be used. Which technician is correct?

  • Technician B

  • Technician A

  • Neither technicians

  • Both technicians

Correct answer: Technician B

It's critical to inspect the insulation before reconnecting a high-voltage battery. To do this, all testing practices and procedures must be performed with an insulation testing tool, making Technician B correct.

Visual inspection may not reveal defects in the insulation, thereby putting Technician A in danger. 

84.

At what point can the technician touch the conductor terminals or damaged conductor?

  • After the de-energizing procedure is complete

  • Whenever repair is required

  • Never

  • Only after a supervisor signs off

Correct answer: After the de-energizing procedure is complete

Technicians shouldn't touch any conductor terminals until the de-energizing procedure is complete. The same is true with damaged conductors.

A confirmation test must prove that there's no high-voltage present in the conductors before touching them. 

85.

When finalizing work on an xEV, which of these steps must be performed?

  • Ensure that every tool and part has been removed from the repair area

  • Remove safety barriers

  • Remove safety cones 

  • Install magnetic car topper

Correct answer: Ensure that every tool and part has been removed from the repair area

It's essential that every tool and part is removed from the repair area when the technician is finished. Nothing should be left behind. This step is part of planning and documenting that all work that is done. 

Safety barriers and equipment aren't ready to be removed until after the work is completed and the area has been inspected. 

86.

What is configured as a series circuit with multiple switches or connectors attached to a low voltage power source?

  • Interlock circuits

  • Low-voltage buttons

  • Switching voltage selectors

  • High-voltage circuits 

Correct answer: Interlock circuits

There could be one or more interlock circuits integrated into the high-voltage components of EVs. The interlock circuit is configured as a series circuit with multiple switches or connectors attached to a low-voltage power source. This low voltage source is typically 5V or 12V.

When the connectors are seated and switches are closed, current goes through the interlock circuit, providing a significant voltage drop. 

87.

What is the equation to determine how much current will pass through the body based on the power source?

  • I = V/R

  • C = R/V

  • I = V+R

  • I = V-R

Correct answer: I = V/R

To calculate the amount of current that would pass through a person's body, you want to use I = V/R. Take the voltage and divide it by the resistance. 

As an example, if the source has 400 V and the resistance is 600 ohms, the total current would be 660 mA (400/600). That equates to more than eight times the 75 mA lethal limit. 

88.

At what point can a Level 2 technician replace high-voltage cables or connectors?

  • After the high-voltage battery has been disconnected

  • Never, only a Level 3 technician can perform these tasks

  • Whenever they need to be replaced

  • Never, these parts aren't meant to be replaced

Correct answer: After the high-voltage battery has been disconnected

Once the high-voltage battery is disconnected and the components are confirmed to be de-energized, the cables and connectors can be replaced. All parts must be secured with the appropriate Lockout/Tagout procedures.

It's important to follow all Original Equipment Manufacturer (OEM) guidelines when working with high-voltage systems. Level 3 technicians are also qualified to do this work. 

89.

How many digits does an Ingress Protection (IP) rating have?

  • Two

  • One

  • Zero

  • Three

Correct answer: Two

The Ingress Protection (IP) rating is made of two digits. This rating specifies the water and dust resistant standards.

The first digit specifies the size of excluded objects, while the second digit shows the water protection level. 

90.

Why must the Level 2 technician know how to secure the high-voltage system?

  • So it doesn't become activated

  • So nothing gets stolen

  • To keep it from getting lost

  • To add an extra cost to the bill

Correct answer: So it doesn't become activated

Power must be isolated from the high-voltage system while it's being worked on. If the current were to start flowing, it could cause electrical shock and injury.

Therefore, a Level 2 technician must understand how to secure the high-voltage system and keep it from activating. They must also know how to isolate voltage from the systems. 

91.

Which of the following items isn't part of the electrified propulsion vehicle (xEV) Service Safety Kit?

  • Retrieval hook

  • Magnetic car topper

  • Class-0 electrical safety gloves

  • Glove leak tester

Correct answer: Retrieval hook

All Service Safety Kits should include a magnetic car topper, along with caution barricades and cones to create a safety zone around the vehicle. It should also include caution tape and a fire extinguisher.

In conjunction with those parts, this safety kit should include Class-0 electrical safety gloves and leather over-gloves. It also needs a glove leak tester and protective shield head gear. The retrieval hook is a safety item that should be located somewhere in the shop for emergency use.  

92.

Technician A says that cleaning sprays can be used around high-voltage circuits. Technician B believes that cleaning sprays should never be used around high-voltage circuits. Which one is correct?

  • Technician B

  • Technician A

  • Both 

  • Neither

Correct answer: Technician B

No sprays should be used around high-voltage circuits, including cleaning sprays. This moisture can energize the ionized air around the circuit, making it conductive. 

A 400 V DC circuit has more potential to produce an electrical arc than a 12 V DC circuit. 

93.

How long should a technician wait to touch high-voltage terminals or connectors after disabling the system with the Manual Service Disconnect (MSD) or other manufacturer method?

  • Prescribed time by Original Equipment Manufacturer (OEM)

  • One minute

  • Five minutes

  • Ten minutes

Correct answer: Prescribed time by Original Equipment Manufacturer (OEM)

Once a technician has disabled the system with the Manual Service Disconnect (MSD) or other methods outlined by the automaker, it's important to wait the prescribed time by the OEM before touching any high-voltage terminals or connectors. 

Every manufacturer has different guidelines, so there's no blanket rule giving a time. Refer to the OEM instructions and guidelines set at the workplace. 

94.

What should be done if the work requires exposure or disconnection of high voltage?

  • Take reading between all high-voltage cable ends and ground

  • Use both hands to touch cables

  • Technician puts on conductive equipment

  • Ask the LEVEL ONE technician to do the work

Correct answer: Take reading between all high-voltage cable ends and ground

If the service work requires disconnecting high-voltage cables or exposure, additional testing must be performed. The technician must take a reading to confirm there's no voltage between the high-voltage cable ends, and the high-voltage cable ends and the ground. It's recommended to perform this work with the help of another technician present. 

Technicians should never use both hands to touch high-voltage cables. They should never have conductive accessories or equipment on them while working around high-voltage systems. 

95.

Which of the following is the technician permitted to wear while working on EVs?

  • Arc Rated (AR) clothing

  • Metal belt

  • Jeans with change in the pocket

  • Jewelry

Correct answer: Arc Rated (AR) clothing

Arc Rated (AR) clothing is permitted by the NFPA regulations. The minimum arc rating depends on what type of voltage is being worked on.

Conductive materials should never be worn while working on EVs. Any conductive material should also be removed from the pockets before starting to work. 

96.

What can be used to insulate exposed high-voltage terminals that have been disconnected?

  • Electrical tape

  • Cleaning spray

  • Rubber foam

  • Duct tape

Correct answer: Electrical tape

Electrical tape can be used to insulate high-voltage terminals that are disconnected. No other material should be used for this purpose.

It's also critical to avoid using any sprays around high-voltage terminals and circuits. 

97.

Which of these is not a complication of cutting into high-voltage wire while testing?

  • Faster charging times

  • Dangerous shorting condition

  • System disabled

  • Cable damage

Correct answer: Faster charging times

Cutting into high-voltage wire during testing is not going to create faster charging times. Technicians are never permitted to cut or pierce high-voltage wiring for testing.

Doing so creates the possibility for a dangerous shorting condition. It can also disable the system and leave permanent cable damage. 

98.

What must a technician do before getting the Level 3 certification?

  • Attain Level 2 qualifications

  • Work 40 hours as a service technician

  • Own Personal Protective Equipment (PPE)

  • Drive an EV

Correct answer: Attain Level 2 qualifications

The Level 3 technician will also have achieved the Level 2 certification. They must also have training for high-voltage battery packs.

Level 3 technicians are qualified to perform "live" work, so they must understand the risks and learn how to reduce hazards. 

99.

What needs to be done if there's a trouble code entry stating, "Loss of Isolation?"

  • Disconnect high-voltage components

  • Probe high-voltage connectors

  • Re-install the Manual Service Disconnect (MSD)

  • Test the high-voltage battery

Correct answer: Disconnect high-voltage components

When a trouble code entry says either "Loss of Isolation" or "Insulation Resistance Too Low," technicians need to disconnect the high-voltage components. By disconnecting these components, the technician can diagnose the loss of isolation at the component level.

Level 2 technicians are not authorized to test the high-voltage battery or work on it. 

100.

What tool is used to verify that no voltage is present at the contactors after de-energizing?

  • Digital multimeter

  • Clamp meter

  • Earth ground tester

  • Light tester

Correct answer: Digital multimeter

It's required to use a CAT III 600 V, CAT III 1000 V, or CAT IV 600 V Digital Multimeter (DMM) to verify there's no voltage present at the contactors. This is to be done after the Absence of Voltage Verification Process (E4) is performed. 

De-energizing occurs first, as per the Original Equipment Manufacturer (OEM) instructions. After that, technicians must verify the system can't be re-energized, which is also when the system is checked for voltage with a digital mutimeter.