AUTO 480 Final
Which of the following should the tech be looking at after a collision before putting the pack back into service?
The tech should check for connector, harness, and battery pack damage
When looking to inspect/disconnect an electrical component from the high-voltage system for testing, what should the technician do before removing the component from the circuit?
The tech should follow depowering procedures indicated by the OEMs service info before removing the component from the system.
When acquiring PPE, what should the technician do before using it on a high-voltage circuit?
The tech should make sure the equipment fits properly and has a valid certification.
How should the technician test the high-pressure system pressure in the high-pressure fuel injection system?
The technician should use a scan tool to measure system pressure from the rail fuel pressure sensor
If the pack's cooling system is compromised from a line leakage or pump failure, which of the following could be a result of a failing pack cooling system?
Accelerated cell aging and, if extreme, thermal runaway may occur, which could cause a pack failure or a fire within the vehicle
The intake stroke of an SI PFI engine is where the intake valve opens and what enters the cylinder?
Air-fuel mixture
Local interlock circuits allow the controller to monitor what is happening where within the vehicle?
At the particular component that the interlock is connected to.
The HCCI engine still has an engine cycle that has valve events and a combustion event. Which of the following is an applicable cycle that a HCCI engine could use?
Atkinson cycle
Which of the following types of engine cycles is the most commonly used on the ICE of an HEV?
Atkinson cycle
All of the following affect the ability of a combustion event, EXCEPT:
Engine configuration
When the NiCad battery becomes fully charges, there is a large bump to indicate it is full. The NiMH battery does not have this bump. How does this affect the battery pack when it is charging?
Failed cells can cause charging to cease prematurely
To help with maintaining proper power inverter operation, the inverter must be cooled. When diagnosing an inverter failure or high-temp condition, what should the tech do first?
Inspect the cooling system to the inverter and determine its condition
Centralized HEV/BEV high-voltage components eliminate the need for which of the following?
Interlock circuit
The purpose of the DC-DC converter is to create which of the following?
It converts the battery pack voltage from high voltage to low voltage to operate vehicle accessory systems
The cylindrical shape of cell architecture is useful because of which of the following?
It is easily packaged together and minimizes effects of vibration
An early model of a GDI equipped engine has a rattling sound emitting from the intake manifold area. What is the source of this noise?
It is the combination of the high-pressure fuel injector operation and the combustion process.
The HCU utilizes hydraulic control solenoids to operate each wheel independently of the brake pedal. How does the HCU use these solenoids to control the operation of the different wheels on the vehicle?
It pulses the solenoids on hold or release to maintain wheel rotation and maintain tire friction coefficient
A bus capacitor is used to do what for the inversion process within the inverter?
It smooths out the harmonics that cause noise produced by the inversion process
Why does the AC propulsion motor need three AC waveform phases supplied to it to operate properly?
It uses three phases to increase torque and efficiency, supplying current to three stator winding groups at 120 electrical degree intervals
Which of the following SAE recommended practices relates to HEV/BEV battery crash-testing integrity?
J1766
What type of electrolyte is used in a NiMH battery to allow the transfer of ions from the cathode to the anode?
KOH
Which type of energy within a vehicle a moving vehicle is used for a regenerative braking system?
Kinetic
When rear wheels start to slip and the rear end of the vehicle starts to slide, which of the following could happen to the direction of the vehicle's front wheels moving at a sharper angle than the rear of the vehicle?
Oversteer
In order to understand how the high-voltage system is powering the propulsion system, the tech must understand how the vehicle is being charged. Which of the following vehicles has the ability to be charged from two sources?
PHEV
Which of the following are some of the barriers to mass adoption of electric vehicles in the United States?
- Initial cost of the vehicle and change of driving habits - Availability of charging stations in the country - Customer's views of BEV
When diagnosing an AFM failure, the tech notices a noise from the engine valley area underneath the intake manifold. Which of the following could affect the AFM and also make a mechanical noise?
A broken lifter return spring
When diagnosing a CI issue, a possible cause of a misfire or increases emissions situation could be which of the following?
Poor quality fuel
Which if the following is a reason that the Atkinson-cycle engine is used for a hybrid application?
The Atkinson cycle creates higher efficiency with a loss of low speed power compared to an Otto-stroke engine
When the Atkinson cycle is implemented, how does the engine increase fuel mileage while NOT changing the rotating assembly?
The Atkinson cycle is a valve train strategy that holds the intake valve open longer to reduce pumping loss in the cylinder
What happens to the rotating wheel assembly when a wheel speed sensor becomes inoperative or provides a false reading to the EBCM?
The EBCM will set a DTC for the inoperative wheel speed sensor and disable the ABS and TCS until the problem is repaired
A NiMH battery is utilized in a lot of applications that that previously had NiCad batteries. Why is this type of battery used in these applications?
The cell voltage is the same as a NiCad battery, which makes it easy to change the cell type
Why is gasoline NOT used in a normal CI engine?
The compression ratio of the application will not allow gasoline to be used, as it would explode before the piston gets to TDC
When looking at an ABS complaint on an EV vehicle, what should the technician check first?
The foundation brakes
In an HEV application, what will happen if the ICE is NOT properly maintained and cannot sustain operation?
The high voltage controller can suspend operation of the high-voltage propulsion system if it sees an ICE-related failure.
When looking at a lever type of MSD, what happens if the letter is not fully depressed and locked into the connector?
The high-voltage system will be disabled because the connector is not contacting the terminal in the receptacle.
During regenerative braking event on an induction motor equipped vehicle, how does the stator generate power to charge the battery pack?
The motor controller reduces the stator Hz slower than the rotor RPM, so the stator windings transfer electrical power to the battery pack
When the motor controller signals the power inverter to change the motors generators, how much regenerative braking force does it allow to generator to apply to the wheels?
The motor controller will vary the drive motor (regenerative braking) torque, based on the systems controller, sensor input, and speed of the vehicle
The operation of the passive discharge system circuit requires which of the following to start discharge operations?
The passive discharge circuit is connected to the high-voltage inverter capacitors and will automatically start discharging the high-voltage circuit when the circuit is opened.
The GDI pistons are unique to this type of application. What is the reason for the unique piton head shape?
The piston head shape is related to the location of the fuel injector in the cylinder
The Ah rating of the battery pack tells the technician which of the following?
The rate of amperage output per hour of operation
What does an insulation tester measure when evaluating high-voltage circuit?
The resistance between a high-voltage component or the wiring/cable of the high-voltage system to the vehicle's chassis
The prismatic cell shape is used a lot within HEV, PHEV, and EV applications because of which of the following?
The shape of the cell allows the for easy design of the battery pack and fitment within the application
In the Mazda SPCCI application, the spark plug is used to do which of the following?
The spark plug is used to increase the compression within the cylinder to start the HCCI event
When evaluating the operational integrity of the high-voltage battery pack, individual cells can cause which of the following?
A shorted cell or cells can potentially cause the pack's ability to accept or release power to become compromised
SiC-based IGBTs are used to increase the efficiency in power electronic components because of what reason?
The thermal conductivity is three times higher than its silicon-based components
The regenerative braking system is used to help convert mechanical heat energy back into electrical energy. Which way does it do this?
The vehicle has a motor generator that is connected to the wheel assembly, which charges the battery pack while the vehicle is moving
Which of the following conditions must occur to run an AC isolation fault test on the high-voltage battery pack?
The vehicle must be OFF and wait 20 minutes
All of the following components of the MSD can fail and cause high-voltage system to become disabled EXCEPT:
The wiring of the MSD switch
When using the wrong type of brake fluid within the foundational and antilock braking system, what could happen?
The wrong brake fluid will swell seals and could cause the HCU to fail, which would set a failure DTC
On some GDI equipped vehicles, carbon buildup is common on the back side of the intake valve. Why is this an issue with a GDI engine?
Without the constant washing action of fuel of the back of the valve, deposits are able to perform
When working on high-voltage systems, which of the following can result in the technician being unable to let go of the circuit?
76 mA of DC current
Which of the following ranges ranges of resistance fits a passive discharge circuit?
6,000-15,000 ohms
What should be the nominal voltage of a NiMH cell?
1.25 volts
Which of the following is the temperature for the PROPER operating range of a NiMH battery cell?
10 C to 40 C
The life cycle of a battery cell is determined by the number of times the cell has been cycled. When evaluating a full cycling event which of the following is considered a full event? The numbers below are representative of the vehicle display.
100% SOC to 0% SOC to 100% SOC
Class 0 gloves are rated at which of the following?
1000 volts AC/1500 volts DC
The purpose of lowering the power provided to the vehicle's support electronics is because those components operate off what power level?
12-14 volts
When looking at the FMVSS No. 305 requirement and the more conservative 500 ohm per volt specification for an isolation fault, what is the minimum insulation resistance measurement on a high-voltage propulsion system with a battery pack voltage capacity of 300 volts?
150,000 ohms
An LTO cell composition provides the what type of cell voltage at 100%
2.85 volts
What is the approximate time it takes for the DC isolation fault test to run on the high-voltage system?
45-60 seconds
Without removing the battery pack from the vehicle, the CAN system can be used to interrogate the various modules and cell groups in the pack. Which of the following tests (these are called different names by different OEMs) can the scan tool run?
Battery pack state of health testing
If the HCCI engine has a lean mixture because of a fuel injector failure or a vacuum leak, how will that affect the combustion event?
Because the cylinder doesn't have the correct ratio of fuel to air, the event may not happen.
When transferring power from the battery pack, the power goes through which of the following battery pack components before making it to the traction motors?
Contactor switch
When a converter is trying to lower the output voltage from the input voltage, what type of converter is used?
Buck type converter
Which CAT rating should be the minimum electrical standard a DMM is rated before being used on the high-voltage systems of HEVs/BEVs?
CAT III
Which of the two sensors should a tech look for in a correlation condition in the VVT system?
CMP and CPK
Nickel is used in high-voltage cells for which of the following reasons?
Cell energy capacity
Which of the following class ratings of high-voltage gloves should the technician use when working with high-voltage systems?
Class 0
Which of these is a major advantage of a BEV?
Components can be placed for optimal weight balancing and crash protection
An IGBT is used within a DC-DC converter to do what?
Control DC-DC converter voltage and current output
The evaluation of a cell or pack to provide the amount of current provided and drawn from the cells over a set period of time is called what?
Coulomb counting
What does the manual service disconnect switch do?
Disables the high-voltage battery pack from the high-voltage propulsion system
When looking at a lithium-ion application, ions move from the anode to the cathode through the load. As these ions move through the motor or other electrical device, what is that called?
Electromotive force
Which of the following explains what a battery cycle is?
Fully discharged to 0% SOC and then fully charged to 100% SOC
When comparing NMC and LFP chemistries, which of the following materials is part of the anode?
Graphite
When inverting DC to AC voltage, which of the following is a large byproduct that must be managed to maintain the inverter operation?
Heat created by inverting from DC to AC
How is hydrogen stored in an FCV before it is consumed by the fuel cell?
High-pressure gas
Which of the following best describes the purpose of the high-voltage bus discharge circuits?
High-voltage bus discharge circuits discharge the energy in the high-voltage system (outside of the high-voltage battery pack) when the vehicle is switched off.
When evaluating a cooling system on a DC-DC converter, the technician must first determine what?
If the DC-DC converter is air-cooled or liquid cooled
A GDI injector operates on a higher voltage than a conventional port fuel injector. In some situations, the injector events can happen at different times, and sometimes there are multiple injections per mechanical cycle. Why does this happen in a GDI engine and NOT in a port fuel equipped engine?
In a GDI equipped engine, the injector is positioned directly in the cylinder, which allows it to operate independently of the mechanical intake valve
In relation to a serial interlock system, which of the following statements are true?
In a serial interlock system, each component is linked together in a daisy chain type of configuration
The PHEV is an intermediate step from a conventional HEV to a BEV. Why does the battery range on a PHEV average 21 miles when compared to the longer range of the BEV?
Most people drive less than 30 miles a day, meaning the vehicle should make it through the day on minimal ICE usage before having to be plugged in.
The FMVSS No. 305 standard was produced by which of the following agencies?
NHTSA
A prismatic cell is used in a lot of applications because of its ability to be assembled in a way that will maximize the pack's capacity. To accomplish this, the prismatic cell is which shape?
Rectangular
Which of the following types of PPE is used when working in a HEV/BEV?
Rubber-soled shoes
Which SAE standard regulates the shape, amperage capacity, and communication requirements of the charging connector that is plugged into a BEV?
SAE J1772
A PHEV allows the operator of the vehicle to charge the vehicle at home or anywhere with access to an electrical socket. What happens if they travel further than the electrical charge capacity?
The ICE will start to drive a generator for power to propel the vehicle
To invert DC to AC power, what must happen to generate the proper type of sinewave output?
The IGBTs must be switched on and off in a specific sequence, frequency, and amplitude to generate a usable AC power sinewave
Which of the following does a hybrid ICE do to help increase the efficiency within the engine operation?
The PCM manipulates the intake valve timing during the intake stroke
The ability to change the engine's valve events in a wide range allows the PCM to fit the engine to its particular situation. Using that info, select the proper statement that explains how the PCM determines how to operate.
The PCM utilizes all of the sensors on the engine, along with driver input sensors, to determine the proper operational conditions for the ICE.
How does the TCS determine if the vehicle is in a situation that requires TCS operation?
The TCS system utilizes the wheel speed sensors of the ABS to monitor vehicle slipping conditions
What does a battery pack's kWh rating refer to?
The amount of kilowatt output per hour of operation
What is a byproduct of the DC-DC converter converting high voltage to low voltage?
Thermal conductance
When utilizing Lithium Ion battery cells which of the following may happen if a cooling system or overcharging even occurs?
Thermal runaway could happen and cause a battery pack fire
When HEVs/BEVs are designed, why are governmental standards and regulations needed for the designers?
These regulations are necessary to minimize the variation between terminology and safety systems to make all high-voltage vehicles safe for the operator.
The cathode is where the ions are stored in a charged cell. When power is called for, where do the ions migrate to?
They move through the circuit to the anode
How does the PCM change the compression ratio of the engine in Nissan's VC technology during operation?
Utilizing an actuator, the PCM shortens the stroke of the connecting rod, thus limiting the piston travel and minimizing friction
When looking at an HEV, how does VVT help keep the engine in compliance with governmental regulations and help ICE operation?
VVT optimizes engine operation to increase efficiency and decrease emissions
When the regenerative braking event happens, the vehicle control module will monitor which component to determine what level of regen to apply?
Wheel speed sensor
When looking at the RMF control of an induction motor, which of the following will turn the motor into a charging component when in regenerative braking mode?
When RMF is turned off, the rotor converts to its power generation mode within the housing
