AUT - 124 Final Exam
A vehicle is being diagnosed for poor A/C performance. The engine is started, and when the system is set to MAX A/C, the compressor engages normally. When the temperature control knob is moved from hot to cool, only hot air blows out of the A/C outlets. Technician A says there is a problem with the air duct system or the controls. Technician B says the system is low on refrigerant. Who is correct?
a only
Occupant classification sensors are being discussed. Technician A says the sensor uses a silicone-filled bladder in the seat cushion that has a pressure sensor connected to it. Technician B says that piezoresistive sensors are located between the seat track and the floor. Who is correct?
a only
Technician A says a cable-driven speedometer unit depends upon magnetism to move the needle. Technician B says the vehicle speed sensor used with an electronic speedometer is typically mounted near one of the vehicle drive wheels. Who is correct?
a only
Technician A says a faulty unlock relay could cause the power door locks to lock but not unlock the doors. Technician B says a faulty actuator could cause this. Who is correct?
a only
Technician A says during a frontal collision, the backup power supply will deploy the air bag if the battery is disconnected. Technician B says all backup power supplies will power down one minute after the negative battery is disconnected. Who is correct?
a only
Technician A says hybrid vehicles use electrically driven high voltage A/C compressors. Technician B says the compressors for hybrids use the same refrigerant oil as regular vehicles. Who is correct?
a only
Technician A says the refrigerant oil container should not be opened until it is time to use it and should be capped immediately after use. Technician B says after the system has been opened, compressed air should be used to flush dirt, moisture, and old refrigerant oil out of the system. Who is correct?
a only
Technician A says two-stage air bags may not always fully deploy. Technician B says two-stage air bags are only used on the driver's side. Who is correct?
a only
Technician A uses the ohmmeter function of a DMM [digital multimeter] to test the resistor block for opens. Technician B tests the resistor block with a lab scope. Who is correct?
a only
Technician A uses the vehicle's built-in bubble level to adjust headlight vertical aim. Technician B uses a screen at ten feet from the vehicle to aim headlights. Who is correct?
a only
Technician A says air in the system can cause excessive pressure within the A/C system. Technician B says moisture can cause freeze-up at the expansion valve. Who is correct?
both
Technician A says an oil pressure sending unit may be tested with an ohmmeter. Technician B says an engine coolant temperature sending unit may be tested with an ohmmeter. Who is correct?
both
Technician A says evacuating (pumping down) an air-conditioning system removes air and moisture from the system. Technician B says evacuating (pumping down) an air-conditioning system must be done anytime the system has been opened for repairs. Who is correct?
both
Technician A says hybrid vehicles have an electric water pump to circulate coolant through the heater core when the engine is stopped. Technician B says hybrid vehicles have a hot
both
Technician A says pinhole leaks in the evaporator may be caused by acid formed when water and refrigerant are mixed. Technician B says leaks are most often found at hose connections and at the various fittings and joints in the system. Who is correct?
both
Technician A says when the SIR warning light is illuminated all the time, there is a fault code stored in the SIR control module. Technician B says if the warning light is on, the air bag system is turned off and the air bag will not deploy in an accident. Who is correct?
both
The reasons for slower than normal wiper operation are being discussed. Technician A says the problem may be in the mechanical linkage. Technician B says there may be excessive resistance in the electrical circuit. Who is correct?
both
Trouble code extraction is being discussed. Technician A says codes may be flashed by the air bag lamp. Technician B says a scan tool may be used. Who is correct?
both
What do the two-speed permanent magnet type wiper motors generally use to achieve the two speeds?
brushes
The park distance control system warns the driver that the vehicle is close to an obstacle by _____.
an audible signal that increases in frequency as the vehicle gets closer
The rain sensor in an automatic windshield wiper system is located ______.
at the top/center of the windshield
A customer complains that the turn signal indicator flashes unusually fast when the turn signal switch is in a left turn position. Technician A says the left side turn signal flasher is defective. Technician B says one of the left turn signal bulbs is the wrong wattage. Who is correct?
b only
Second generation air bag systems are being discussed. Technician A says a second generation air bag inflates with about 20 to 35 percent more energy. Technician B says second generation air bags reduce the number of injuries caused by the air bag itself. Who is correct?
b only
Technician A repairs a leaking heater core. Technician B replaces it with a new core. Who is correct?
b only
Technician A says a CCOT system has an expansion valve and a sight glass. Technician B says a CCOT system has an accumulator. Who is correct?
b only
Technician A says all the refrigerant oil in the A/C system is contained inside the compressor. Technician B says the oil circulates throughout the entire A/C system and at any given moment each component holds a small amount of oil. Who is correct?
b only
Technician A says if the seat belt retractor does not retract when the belt is disconnected, the retractor must be replaced. Technician B says if a seat belt is cut, it must be replaced. Who is correct?
b only
Technician A says on all vehicles, the fuse that protects the backup light system is the same fuse that protects the turn signal system. Technician B says vehicles equipped with automatic transmissions use a combination backup/neutral start switch. Who is correct?
b only
Technician A says that the clockspring is located at the bottom of the steering column. Technician B says that the clockspring maintains electrical contact between the inflator module and the rest of the system. Who is correct?
b only
Technician A says the compressor can pump both liquids and vapor. Technician B says the compressor is driven off the crankshaft by a belt. Who is correct?
b only
Technician A says the receiver/drier is located on the low [pressure] side of the A/C system. Technician B says the accumulator is located on the low side of the system. Who is correct?
b only
Technician A says the sight glass is located in the suction line, between the accumulator and compressor. Technician B says the sight glass is located on the receiver/dryer. Who is correct?
b only
Technician A says when the pressure applied to a liquid is increased, the boiling point decreases. Technician B says when the pressure on a liquid is suddenly released, heat energy is absorbed into the liquid. Who is correct?
b only
Technician A stores recycled refrigerant in emptied new refrigerant tanks. Technician B stores recycled refrigerant in UL-approved containers. Who is correct?
b only
A pyrotechnic-type pretensioner can be tested with a(n) ______.
cannot be tested
Which of the following is NOT a true statement regarding HID headlamps?
come on instantly
The refrigerant is at its lowest pressure and temperature at the ______.
evaporator orifice
Which of the following components is NOT part of a receiver/drier?
expansion valve
Which of the following is NOT a system used for automotive power seats?
five way system
Circuits that can energize the high beams even if the headlight switch is off are known as ____ circuits.
flash to pass
Which of the following types of sensors is NOT used to trigger an alarm system?
infrared heat
The halogen element that is used in most halogen lightbulbs is ______.
iodine
Which of the following is NOT a component of an analog gauge system?
led
The approximate deployment time for most air bags is ______.
less than 100 milliseconds
What is the life expectancy of an LED headlight?
life of vehicle
In an NTC-type thermistor, when the temperature is high, the resistance is ______.
low
When diagnosing air bag diagnostic codes, the order in which the codes are diagnosed is ______.
lowest to highest
A blower motor does not work on three of the four speeds but works on high. Technician A says a faulty blower high speed relay is the cause. Technician B says a faulty blower switch may be the cause. Who is correct?
neither
Technician A says the normal operating pressures of R-134a are slightly lower than the pressures of R-12. Technician B says R-134a boils at 134 degrees Fahrenheit. Who is correct?
neither
Technician A says vanity lights are on whenever the headlamps are on. Technician B says most trunk lights are on whenever the headlamps are on. Who is correct?
neither
Which of the following statements is correct?
none correct
The reflector [aluminum-coated mirror] in a light fixture can be cleaned with ______.
nothing
Normally the A/C system is charged _____ with the engine running.
on the low side as a vapor
The vehicle speed sensor [VSS] for an electronic speedometer on an RWD vehicle is typically mounted _____.
on the transmission output shaft
Rear defrosters generally have a relay with a timer to allow the defogger to ______.
operate for only a specific amount of time
After the wipers are turned off, the ______ switch provides power to the wiper motor until the wipers blades reach the bottom of the windshield.
park
Which of the following is NOT connected to the tone generator [chime module]?
park/neutral safety switch
A precollision system uses _____ to detect possible collisions.
radar
Which of the following is used in an adaptive cruise control system to measure the distance between the vehicle and the vehicle directly ahead of it.
radar
The internal combustion engine in a hybrid does not normally run when the vehicle is at a standstill. What alerts the driver that the vehicle is capable of being driven?
ready light
The compressor on a vehicle has seized. Besides the new compressor, what other component should also be replaced?
receiver/dryer
The stop light [brake light] checker uses a _____ to sense when a brake light bulb is burned out.
reed switch and magnetic coils
The correct procedure for servicing a seat belt pretensioner is to ______.
replace it
Which of the following tools should be used to test an air bag system?
scan tool
The speed of a two-speed electromagnetic field type wiper motor is controlled by ______.
series and shunt field windings that increase the strength of the magnetic field
Large amounts of black dust around the clutch plate is an indication of _____.
slipping a/c belt
The largest and coolest line/hose in the A/C system is the ______ line.
suction
The arrow on an air bag sensor must always face ______.
the front of the vehicle
The boiling point of a liquid increases as ______.
the pressure applied to it increases
A sight glass is normally found on systems using R-12 and a(n) _____.
thermal expansion valve
The leak-test dye in an A/C system will appear luminous yellow-green when illuminated by a(n) _____ light.
ultraviolet
The evaporator is located _____.
under the dash
Which of the following is NOT a type of gauge design?
variable resistance
Which of the following is NOT displayed on the Toyota hybrid multifunction display panel?
voltage of HV battery pack
The light-sensitive photocell sensor/amplifier of an automatic light system is located ______.
within the upper instrument panel pad
A poor heat out of the floor duct condition is being discussed. Technician A says the coolant level in the engine's cooling system may be low. Technician B says the engine's thermostat may be faulty. Who is correct?
both
A six-way power seat is NOT operating in any switch position. Technician A says to check the circuit breaker. Technician B says there may be excessive resistance in the electrical circuit. Who is correct?
both
All gauges do not work. Technician A says the connection to the instrument cluster may be open. Technician B says the cluster's IVR may be open. Who is correct?
both
An R-12 to R-134a conversion procedure is being discussed. Technician A says leak-test the system and conduct a performance test prior to removing the R-12. Technician B says leak-test the system and conduct a performance test after charging the system with R-134a. Who is correct?
both
Headlight circuit protection devices are being discussed. Technician A says the headlight circuit is protected by a self-resetting circuit breaker. Technician B says the headlight circuit is protected by a single maxi fuse. Who is correct?
both
Seat belt retractors are being discussed. Technician A says that when the belt is suddenly jerked on a webbing-sensitive retractor system, the retractor should lock up. Technician B says a vehicle-sensitive retractor can only be tested by braking the vehicle at speeds of 5 to 8 MPH. Who is correct?
both
Technician A always wears safety glasses when working on air-conditioning systems. Technician B makes sure there are no open flames in the area prior to working on the A/C system. Who is correct?
both
Technician A says on some vehicles, if the turn signals blink faster than normal, the problem may be a burned out bulb. Technician B says on some vehicles, if the turn signals don't blink at all, the problem may be a burned out bulb. Who is correct?
both
Technician A says that an air bag module is serviced as an assembly. Technician B says that it is acceptable to replace all the sensors if one is found to be damaged. Who is correct?
both
Technician A says the suction line connected to the compressor should be cool to the touch. Technician B says the discharge line from the compressor to the condenser should be hot along its entire length. Who is correct?
both
Which device on a cruise control system is used to control the amount of vacuum applied to the servo unit?
transducer
How long does it take an HID-type headlight to reach maximum intensity?
15 seconds
Which of the following statements is NOT correct?
The evaporator changes heated refrigerant to a liquid
Air bag safety is being discussed. Technician A says to always carry an undeployed air bag module with the trim facing away from your body. Technician B says to carry the air bag module by its wires. Who is correct?
a only
The purpose of the desiccant bag in a receiver/drier or accumulator is to ______.
absorb moisture inside the system
Pyrotechnic-type pretensioners should be replaced ______.
after deployment of airbag
On which of the following laws of nature is the air-conditioning system based?
all correct
Power window systems use ______.
all correct
The purpose of the air bag diagnostic monitor is to ______.
all correct
Standard sealed beams are typically filled with ______.
argon
A subcooler is located ______.
at the bottom of the condenser
A poor heat condition is being discussed. Technician A says a disconnected engine vacuum hose could not cause the problem. Technician B says a seized blend door could cause the problem. Who is correct?
b only
A technician is diagnosing a vehicle for slow wiper operation. When the linkage from the motor is disconnected and the wiper motor is turned on, the motor runs normally. Technician A says the motor has a poor ground connection. Technician B says the linkage is binding. Who is correct?
b only
A technician is trying, without success, to connect a 30-pound container of R-12 to his R-134a manifold gauge set. Technician A says the R-12 fitting is female and the gauge set fitting is also female. Technician B says the R-134a manifold gauge set uses a half-inch Acme thread, whereas the R-12 tank fitting has a standard thread. Who is correct?
b only
An undeployed air bag is being replaced because the trim cover is cut. Technician A says the cover can be replaced. Technician B says the air bag must be deployed before it is scrapped. Who is right?
b only
An electrochromic outside mirror ______.
darkens as the intensity [glare] of the outside light increases
All the following are items to be checked in gauge systems EXCEPT:
detector switches
Fuel range, ETA [estimated time of arrival], fuel economy and distance to destination are common types of data that are displayed on the _____.
driver info center
An NTC thermistor is used in a(n) _____.
engine coolant temperature sensor
All the following are used as digital electronic displays EXCEPT:
incandescent
Diagnosis of automatic leveling headlight problems is done with a(n) ______
scan tool
A loud squealing noise could be caused by ______.
all correct
Which of the following may be electrically connected in series with the compressor electromagnetic clutch?
all correct
During a performance test, both the low-side and high-side pressures are above normal. Which of the following could cause this problem?
Both "The system is overcharged" and "Insufficient airflow through the condenser"
Technician A says R-12 air-conditioning technicians must be certified. Technician B says R-12 air-conditioning equipment must be certified. Who is correct?
both
Which of the following are NOT usually controlled by the main light switch assembly?
backup lights
The indicator needle on a speedometer is held to the zero position by ______.
a hairspring
A mechanical shield plate or shutter that is moved up and down as the headlights are switched between low and high beams is a feature of a ______-type headlight system.
bi-xenon
All materials or substances, as cold as ______, have heat in them.
-459 F
The filling level of a refrigerant container should never exceed _____ percent of the container's gross weight rating.
60
Which statement concerning HID headlights is NOT true?
HID headlights run hotter than halogen headlights
Which of the following statements concerning LED headlights is NOT true?
LEDs contain mercury, which is toxic and environmentally unfriendly
If little or no resistance is felt while operating the temperature control lever, the problem is most likely which of the following?
The control cables have slipped loose from the dash control or door arm
Air bag system service is being discussed. Technician A says an air bag simulator can be installed in place of the air bag thereby allowing accurate testing of the circuits without the fear of accidental air bag deployment. Technician B says sensors are checked by back-probing the connector. Who is correct?
a only
Composite headlights are being discussed. Technician A says they have replaceable bulbs. Technician B says a cracked or broken lens will prevent the operation of a composite headlamp. Who is correct?
a only
Electronic leak detectors are being discussed. Technician A checks for leaks with the engine off, the shop doors closed, and the overhead fans turned off. Technician B checks for leaks outdoors with the engine running. Who is correct?
a only
Flash-to-pass systems are being discussed. Technician A says the high beam filament is turned on when the flash-to-pass switch is closed. Technician B say the flash-to-pass system only works when the headlights or parking lights are turned on. Who is correct?
a only
Smart keys are being discussed. Technician A says the smart key must be inserted into a slot in the instrument panel before the engine can be started. Technician B says some smart keys can unlock the doors and allow the engine to be started when the smart key is within a few feet of the vehicle. Who is correct ?
a only
Technician A says European and Japanese manufacturers shipping vehicles to the US will eliminate R-134a A/C systems by 2017. Technician B says the United States will switch to R-22 in 2015. Who is correct?
a only
Technician A says R-12 is a chlorofluorocarbon (CFC) that damages Earth's ozone layer. Technician B says R-134a is a hydrofluorocarbon (HFC) that causes even greater damage. Who is correct?
a only
Technician A says that air bag systems may use up to five sensors. Technician B says all sensors are located in the passenger compartment. Who is correct?
a only
The right front window does NOT function on a power window vehicle. Technician A states that there may be an open in the window motor circuit. Technician B states that either the master switch or right door switch could be defective. Who is correct?
a only
Frost on the outside of the receiver/dryer, but not on the liquid line between the condenser and receiver/dryer indicates ______.
a restriction in the receiver/dryer
Heater control valves are operated by a ______.
all answers
Inspection verifies that none of the power windows moves up or down when either the master switch or the door switches are toggled. What could be the problem?
all answers
The air bag control module determines whether the seat is occupied by a child, adult, or a child in a booster seat by inputs from the _____ sensor.
all answers
Airflow control valves in the ventilation duct work are operated by ______.
all correct
The rear light assembly typically includes the ______.
all correct
An open in one of the heated rear window grid elements can be repaired by ______.
applying a thin strip of a repair compound to the damaged area
The owner of a vehicle with automatic headlights complains that the headlights are always on whenever the vehicle is driven; even in broad daylight. What is the first thing you should check?
articles placed on top of the dash
Cruise control systems are being discussed. Technician A says the cruise control system uses a governor valve operated by automatic transmission fluid [ATF] pressure to control the throttle. Technician B says vehicles that use electronic throttle control [throttle by wire] do not require a separate cruise control module, stepper motor, or cable to control engine speed. Who is correct?
b only
R-12 to R-134a conversions are being discussed. Technician A says the original receiver/dryer or accumulator should not be replaced. Technician B says permanently install conversion fittings using a thread-locking chemical. Who is correct?
b only
Technician A says there should be a gradual change from hot to warm as you move your hand along the return bends of the condenser from the bottom to the top. Technician B says a restriction in the condenser will be evident by a sudden change in temperature. Who is correct?
both
Technician A uses a powered test light to check a lightbulb. Technician B uses an ohmmeter. Who is correct?
both
Tire pressure monitor systems are being discussed. Technician A says that when the indicator light is yellow, the pressure in one of the vehicle's tires is below minimum. Technician B says that when the indicator is red, the tire pressure is excessively low or almost flat. Who is correct?
both
Windshield wiper motors are being discussed. Technician A says wiper motors are permanent magnet type motors. Technician B says wiper motors are electromagnet field type motors. Who is correct?
both
The powdery substance released from the air bag when it is deployed is ______.
both "cornstarch" and "talcum powder"
The master control switch for a power window provides ______.
both "electrical power for the window motor" and "the ground for the window motor"
______ gas is used to inflate an air bag module.
both argon and nitrogen
The EPA-approved certification exam on refrigerant recovery and recycling is administered by _____.
both ase and macs
The stoplight switch is normally mounted on the ______.
brake pedal arm
Heater cores with electric PTC heater strips are used on what type of vehicle?
hybrid vehicles
The event data recorder is located ______.
inside the air bag sensor assembly [ASDM]
A compressor clutch that chatters when the A/C is off could be caused by _____.
insufficient clearance between the rotor pulley and the armature plate
Which of the following oils can be used in an R-134a system?
pag oil
