ASE L3 Exam Questions

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181.

EV electric motors are also known as which of the following?

  • Traction motors

  • Slipping motors

  • Clutchless motors

  • Wet motors

Correct answer: Traction motors

Electric motors used in EVs are also known as traction motors.

182.

Technician A says on many HEV and PHEV vehicles, ICE is running whenever the vehicle is moving. Technician B says the ICE is only allowed to run under certain conditions. Who is correct?

  • Technician B

  • Technician A

  • Both A and B

  • Neither A nor B

Correct answer: Technician B

Only technician B is correct. On many HEV and PHEV models, the ICE is only allowed to run under certain conditions.

183.

Which of the following should be used to measure the resistance between generator interphase windings? 

  • Milliohmmeter 

  • Megohmmeter

  • Oscilloscope 

  • Scan tool

Correct answer: Milliohmmeter 

A milliohmmeter is a precision instrument used to measure resistance between interphase windings. 

184.

All the following battery types are currently used as hybrid high-voltage batteries, except:

  • Lithium cobalt oxide

  • Lithium-ion

  • Lithium-polymer

  • Nickel-metal hydride

Correct answer: Lithium cobalt oxide

Lithium cobalt oxide batteries do not perform well in high-load applications. These batteries tend to be used in consumer electronics, such as phones and tablets.

All the other battery types are currently used as high-voltage hybrid batteries.

185.

All the following are true regarding regenerative braking except:

  • Energy recovered during regenerative braking is stored in the inverter.

  • Regenerative braking takes place by releasing the accelerator pedal.

  • It is similar to engine braking with an internal combustion engine.

  • Regenerative braking can lead to rotor rust.

Correct answer: Energy recovered during regenerative braking is stored in the inverter.

Energy recovered during regenerative braking is stored in the high-voltage battery. All the other options are true, including regenerative braking leading to rotor rust. This is because the mechanical brakes aren't used as often as they are on a traditional vehicle. 

186.

In a series-parallel hybrid, the generator is connected to what?

  • Sun gear

  • Ring gear

  • Planet gears 

  • Planet carrier 

Correct answer: Sun gear

Series-parallel hybrids use a power-split device and a planetary gear set. In this system, the generator is connected to the sun gear.

187.

Technician A says trapped air in a cooling system will eventually bleed out on its own. Technician B says improper coolant bleed procedures can cause engines to overheat and cause potential damage.

  • Technician B

  • Technician A

  • Both A and B

  • Neither A nor B

Correct answer: Technician B

Only technician B is correct. Not performing the cooling system bleed and fill procedures correctly can cause air to stay in the system.

188.

Technician A says electric compressor clutches are much stronger than conventional compressors. Technician B says POE oil is hygroscopic. Who is correct?

  • Technician B

  • Technician A

  • Both A and B

  • Neither A nor B

Correct answer: Technician B

Only technician B is correct. POE oil is hygroscopic. Electric compressors eliminate the need for clutches and belts.

189.

Technician A says it can be difficult to add fuel when the tank gets low in some hybrids. Technician B says the capacity of some fuel tanks is affected by ambient temperature. Which technician is correct?

  • Both A and B

  • Technician A

  • Technician B

  • Neither A nor B

Correct answer: Both A and B

Both technicians are correct. Some hybrids use a bladder-type fuel tank made of resin, which is affected by temperature. As the ambient temperature drops, the bladder contracts, affecting capacity. As the fuel level gets low in some tanks, such as the early Toyota Prius, it can become more difficult to add fuel.

190.

Technician A says class zero gloves should be sent out every 12 months to be tested. Technician B says class zero gloves should be sent out every 6 months to be tested. Who is correct?

  • Technician B

  • Technician A

  • Both A and B

  • Neither A nor B

Correct answer: Technician B

Only technician B is correct. Electrical testing by a laboratory should be done every 6 months.

191.

A technician is checking a high-voltage cable for opens with a megohmmeter and gets a reading of 0 volts. What does this indicate?

  • A good cable 

  • An open circuit 

  • A short to ground 

  • High resistance in the cable 

Correct answer: A good cable

A reading of 0 volts indicates a good cable. On the other hand, a reading of 1020 volts/2.2 gig ohms indicates an open circuit. The megohmmeter meter applies high voltage to the cable, and the test checks to see if any of that voltage has leaked out.

192.

All the following can affect inverter operation except:

  • Open stator windings

  • Weak rotor magnets

  • Low transmission fluid level

  • Overheating

Correct answer: Open stator windings

Shorted stator windings can affect inverters and even cause them to fail, not open stator windings.

193.

According to the Hybrid/Electric Vehicle Specialist Certification Test Reference Blocks, all systems are equipped with a DC/DC converter to replace which component?

  • Alternator

  • 12V battery

  • Electric motor

  • Battery pack

Correct answer: Alternator

Every system contains a DC/DC converter that supplies stepped-down voltage to the 12V system. This converter replaces the traditional alternator (generator).

This system doesn't replace the 12V battery, battery pack, or electric motor.

194.

Which of the following is the first step to take before removing a high-voltage battery?

  • Make sure the ignition key is removed and the vehicle is in "not ready" mode

  • Remove the negative 12-volt battery cable

  • Remove the high-voltage service plug

  • Test the voltage at the battery cables with a CAT III meter

Correct answer: Make sure the ignition key is removed and the vehicle is in "not ready" mode

Although all the options are steps that should be taken before removing a high-voltage battery, the first step is to make sure the ignition key is removed and the vehicle is in "not ready" mode.

195.

Where should a technician connect the meter to check that a high-voltage capacitor has discharged?

  • Between the positive and negative HV cables that attach to the component being tested

  • Between the positive HV cable and ground 

  • Between the negative HV cable and power 

  • Between the motor/generator phase cables 

Correct answer: Between the positive and negative HV cables that attach to the component being tested

To ensure a high-voltage capacitor has completely discharged, a technician should connect a CAT III meter between the positive and negative HV cables that attach to the component.

196.

Technician A says a boost converter is used to boost hybrid battery voltage. Technician B says a boost converter helps provide more power to the electric motors. Who is correct?

  • Both A and B

  • Technician A

  • Technician B

  • Neither A nor B

Correct answer: Both A and B

Both technicians are correct. A boost converter is used to boost hybrid battery voltage to provide more power to the electric motors. 

197.

What RPM will a Toyota Prius idle at when in the mode for continuous running for diagnostics?

  • 1000 RPM

  • 750 RPM

  • 550 RPM

  • 1200 RPM

Correct answer: 1000 RPM

When the Prius is continuously running for diagnostics, it will idle at 1000 RPMs.

198.

Technician A states that the best way to extend the life of the lithium-ion battery is to allow it to discharge completely before recharging. Technician B states that the battery charge should be between 10% and 90% to extend its life. Which technician is correct?

  • Neither A nor B

  • Technician A

  • Technician B

  • Both A and B

Correct answer: Neither A nor B

Both technicians are incorrect. To extend the life of a lithium-ion battery, it's best to keep it charged between 20% and 80%. Some PHEVs prevent drivers from using the bottom or upper 20 percent, such as the Chevrolet Volt.

199.

Technician A says when diagnosing a no crank, no start condition ICE on a hybrid vehicle, make sure to check that the ICE is not seized mechanically. Technician B says to check for DTCs with a scan tool when diagnosing a no crank, no start condition. 

  • Both A and B

  • Technician A

  • Technician B

  • Neither A nor B

Correct answer: Both A and B

Both technicians are correct. When diagnosing an ICE for a no crank, no start, the ICE should be checked for free rotations, and DTCs should be checked using a scan tool.

200.

Technician A says the PCM is a form of DC/DC converter. Technician B says the hybrid system DC/DC converter is a kind of transformer. Who is correct?

  • Both A and B

  • Technician A

  • Technician B

  • Neither A nor B

Correct answer: Both A and B

Both technicians are correct. The PCM is a type of DC/DC converter since it receives 14 volts and outputs 5 volts. The DC/DC converter is a type of transformer in which higher voltage is converted to lower voltage.