ELECTRICAL 2 FINAL (quiz/exam questions)
Which of the following is an example of a piezoelectric sensor? oil pressure gauge sender unit, knock sensor, coolant temp sender unit, hall-effect sensor
Knock sensor
HID bulbs are being discussed. Technician A says that bulbs contain Xenon gas and sodium bicarbonate. Technician B says that bulbs are constructed of sodium hydroxide and Neon gas. Who is correct?
Neither
Technician A says that interference originating from radiated noise could be caused from poorly routed wires. Technician B says that conducted interference enters the system through the antenna. Who is correct?
Neither
Technician A says that network communication collisions on a LIN circuit are controlled through priority scheduling. Technician B says that LIN networks employ retransmission error handling. Who is correct?
Neither
Technician A says if a circuit is ON 75% of the time, it is operating at a 75% duty cycle. Technician B says when a circuit is duty-cycle controlled, the pulse frequency does not change, only the percentage of ON time compared to total cycle time. Who is correct?
Both
Technician A says in a Smart Key System the Certification ECU pulses the exterior oscillators using a low frequency (LF) signal to "wake up" the key when it is brought into the detection area. Technician B says when a smart key is brought within the detection area an LF signal from the oscillator commands the key to transmit the Vehicle ID Code wirelessly tothe tuner. Who is correct?
Both
Technician A says prior to performing a resistance test between the CAN bus and B+ or ground, the negative battery cable should be disconnected. Technician B says resistance measurements will change significantly when Techstream is connected to the network at DLC3. Who is correct?
Both
Technician A says prior to performing a resistance test between the CAN bus and B+ or ground, the negative battery cable should be disconnected. Technician B says resistance measurements will change significantly when Techstream is connected to the network at DLC3. Who is correct?
Both
Technician A says that "Fading" is a phenomenon that causes the RF signal to be alternately strong and weak. Technician B says that a type of interference called "Multi-Path is caused when an RF signal bounces off something and interferes with the signal received directly causing an echo at the speakers or a scratchy static-like distortion. Who is right?
Both
Technician A says that DC voltage is sent through each speaker circuit to carry the AC voltage signal. Technician B says that the amplitude of the AC voltage signal represents the volume of the sound. Who is correct?
Both
Technician A says that GPS signal reception may be blocked or interrupted in certain locations such as when driving through a tunnel or when adjacent to tall buildings. Technician B says that when any obstacle (including cargo) blocks the GPS antenna, signal reception may be interrupted. Who is right?
Both
Technician A says that MIN/MAX recording mode on the DVOM records minimum and maximum input values and stores them in memory. Technician B says when in MIN/MAX recording mode, a beeper emits a tone when a new minimum or maximum value is recorded. Who is correct?
Both
Technician A says that a short on the MOST data line will create a ring break. Technician B says that an open wake up line will create a ring break. Who is correct?
Both
Technician A says that depending on the system configuration, either the Transponder Key ECU or ECM may need to be replaced if all the keys to the vehicle are lost. Technician B says that later systems were modified so that the ECM or Transponder Key ECU could be reset to accept registration of new keys. Who is correct?
Both
Technician A says that gateway modules translate commands from one network to another. Technician B says that on LIN networks the gateway module is often also the master. Who is correct?
Both
Technician A says that trees, rain and air quality can cause RF loss. Technician B says that window tinting can cause poor reception. Who is correct?
Both
Technician A says the Certification ECU is sometimes called the Smart Key Computer Assembly by the parts department. Technician B says the ID Code Box is sometimes called the Immobilizer Code Computer by the parts department. Who is correct?
Both
Technician A says the Controller Area Network (CAN) uses twisted pair wiring and differential voltage drive protocol with signals on CAN High ranging from 2.5V to 3.5V and the signals on the CAN Low ranging from 2.5V to 1.5V. Technician B says the advantage of twisted pair wiring is that it provides protection from unwanted electromagnetic "noise". Who is correct?
Both
Technician A says the Controller Area Network (CAN) uses twisted pair wiring and differential voltage drive protocol with signals on CAN High ranging from 2.5V to 3.5V and the signals on the CAN Low ranging from 2.5V to 1.5V. Technician B says the advantage of twisted pair wiring is that it provides protection from unwanted electromagnetic "noise". Who is correct?
Both
Technician A says the Main Body ECU receives commands from the Certification ECU to turn lights ON and unlock the doors. Technician B says the Touch Sensor (on the outside handle of the door) signals the Certification ECU that the driver is preparing to enter the vehicle. Who is correct?
Both
Technician A says the Serial Interconnect Line (SIL) is used in some Toyota Multiplex circuits for communication with the TECHSTREAM Unit. Technician B says it is possible for an ECU to appear to be normal on the System Select screen because it is communicating on SIL, even though the CAN line is down. Who is correct?
Both
Technician A says when CAN H and CAN L bus wires are shorted together at anypoint on the bus, it is impossible to generate a differential voltage on each wirefor communication. Technician B says when one of the CAN bus lines (CAN H or CAN L) is shorted to ground, that line's voltage is zero; if shorted to B+, the line's voltage goes to B+. Who is correct?
Both
Technician A says when CANH and CANL bus wires are shorted together at any point on the bus, it is impossible to generate a differential voltage on each wirefor communication. Technician B says when one of the CAN bus lines (CANH or CANL) is shorted to ground, that line's voltage is zero; if shorted to B+, the line's voltage goes to B+. Who is correct?
Both
Technician A says when a pulse-width modulated circuit is power-side controlled, the voltage modulation is observable after the ECU and before the load as shown in the image below. Technician B says most circuits in Toyota vehicles are ground-side controlled and should be measured after the load. Who is correct?
Both
Technician A says you depress the MIN/MAX button on the DVOM to cycle through the maximum, minimum, average, and present readings. Technician B says when the HOLD button is depressed in MIN/MAX recording mode, the recording of the readings stops, the values are frozen, and you can scroll through previously stored readings. Who is correct?
Both
Technician A says do not switch the power mode ON/OFF more than 20 times before completing G Code registration, because doing so may cause the ECM to lock up and stop communicating. Technician B says after replacing a Certification ECU, do not apply power to the system (ignition ON) more than 10 times before performing the Key Registration Procedure, otherwise the Certification ECU locks up and stops communicating. Who is correct?
Tech A
A vehicle's fuel gauge is always indicating a full tank. All of the other instrument gauges are operating correctly. Which of the following is the most likely cause of this problem?
Shorted fuel gauge sender unit
What component transmits the speed sensor signal to the AFS ECU?
Skid control
What does the headlight level actuator use to regulate the angle of the reflectors?
Step motor
A technician is measuring the resistance of a coolant temperature sensor. At cold start the resistance measured 2KὨ. After the vehicle is fully warmed up, the resistance measures 200Ὠ. Technician A says the coolant sensor is operating normally. Technician B says voltage drop at the coolant sensor should increase as resistance decreases. Who is correct?
Tech A
Refer to the figure below. A 2012 Camry with Smart Key has a B27A2 DTC: Open in Front Passenger Side Electrical Antenna Circuit. Technician A says front door outside handle assembly RH (for front passenger door) could be at fault. Technician B says front door outside handle assembly LH (for driver's door) could be at fault. Who is correct?
Tech A
Technician A says on a Generation 2 Prius, if the power switch is cycled from ON to OFF more than 20 times before the Transponder Key ECU and Hybrid Vehicle Control ECU are registered, the Transponder ECU will lock up and need to be replaced. Technician B says on a Generation 2 Prius, when the Hybrid Vehicle Control ECU is replaced, the security code is registered automatically. Who is correct?
Tech A
Technician A says that AFS headlight control is determined using steering angle and vehicle speed inputs. Technician B says that both low and high beams are controlled by the AFS ECU. Who is correct?
Tech A
Technician A says that a flickering HID bulb that goes out, but comes back ON when the key is cycled, is an indicator of fail safe operation. Technician B says that missing HID bulb will cause the system to enter fail safe mode. Who is correct?
Tech A
Technician A says that for security reasons, only Master Technicians and MDTs are authorized to request an immobilizer reset passcode. Technician B says that when the Transponder Key ECU is replaced, the new unit needs to be programmed before registering keys. Who is correct?
Tech A
Technician A says that initialization of the AFS headlights occurs at engine start. Technician B says that initialization does not need to be performed unless a component has been replaced. Who is correct?
Tech A
Technician A says that the LIN network is considered a "master / slave" network. Technician B says that LIN networks are generally configured in ring topologies. Who is correct?
Tech A
Technician A says that the film used on a heated windshield will block some radio or microwave signals. Technician B says that the silver and zinc coating can give the glass a green tint. Who is correct?
Tech A
Technician A says the circuit shown below is a ground-side controlled circuit. Technician B says the transistor in the circuit shown below is a PNP transistor and when voltage is applied to the base, current stops flowing from the collector to the emitter. Who is correct?
Tech A
Bluetooth communication is being discussed. Technician A says that the range of Bluetooth communication is approximately 10 feet. Technician B says that Bluetooth technology provides hands free phone operation and audio playback. Who is correct?
Tech B
Headlight swivel position is being discussed. Technician A says that headlight position is monitored by potentiometers. Technician B says that swivel position is tracked using Hall Effect sensors. Who is correct?
Tech B
MOST network communications are being discussed. Technician A says that the MOST wake-up line is unidirectional. Technician B says that the wake-up line will pass through components that are inoperative. Who is correct?
Tech B
Multiplex networks are configured in a variety of designs often referred to as network topologies. Technician A says in a network with a star topology, if a communication line to one of the slaves has an open, it will interrupt communication on the entire network. Technician B says in a network with a ring configuration, an open in one area of the ring will not interrupt network communication. Who is correct?
Tech B
Multiplex networks are configured in a variety of designs often referred to asnetwork topologies. Technician A says in a network with a star topology, if a communication line to one of the slaves has an open, it will interrupt communication on the entire network. Technician B says in a network with a ring configuration, an open in one area of the ring will not interrupt network communication. Who is correct?
Tech B
Technician A says in most electromagnetic gauges, if the sending unit resistance is low, the gauge will read low. Technician B says in most electromagnetic gauges, if the sending unit resistance is low, the gauge will read high. Who is correct?
Tech B
Technician A says that a bus type network topology uses a central ECU. Technician B says that all ECU's on a bus network can communicate with each other. Who is correct?
Tech B
Technician A says that a vehicle with a heated windshield option will likely have a smaller generator than a vehicle without the option. Technician B says that a sensor may be used to detect damage to the glass and the heated windshield film. Who is correct?
Tech B
Technician A says that pressing the HZ button twice will configure the DVOM to measure frequency. Technician B says that duty cycle is displayed as a percentage. Who is correct?
Tech B
Technician A says that the video waveform is outputted from the camera only when the shift lever is placed in reverse. Technician B says that the camera image is displayed only when the shift lever is placed in reverse. Who is correct?
Tech B
Technician A says the oscillators transmit using UHF waves. Technician B says that keeping the Smart Key near electronic devices may cause the battery to wear out prematurely. Who is right?
Tech B
Two technicians are reviewing the system diagram below: Technician A says disconnecting the skid control ECU would create an open in the CAN bus and will affect the communication on the entire bus. Technician B says disconnecting the combination meter would create an open in the CAN bus and will affect the communication on the entire bus. Who is correct?
Tech B
Two technicians are reviewing the system diagram below: Technician A says disconnecting the skid control ECU would create an open in the CAN bus and will affect the communication on the entire bus. Technician B says disconnecting the combination meter would create an open in the CAN bus and will affect the communication on the entire bus. Who is correct?
Tech B
During smart entry if the dome/puddle lights illuminate you can conclude all of the following are correct, EXCEPT: The key is registered to the vehicle The Steering Lock ECU is functioning The Main Body ECU (or equivalent) is functioning Communication between the Certification ECU and The Main Body ECU is good
The steering lock ECU is functioning
Technician A says, during smart entry, when the Certification ECU verifies the code received from the tuner is a registered Key ID Code, the dome light and puddle lights on the mirror (if equipped) illuminate. Technician B says during smart entry, when the Certification ECU commands the Main Body ECU to unlock the door, a double beep sounds, the vehicle lights flash, the driver's door unlocks and the driver's door oscillator stops pulsing. Who is correct?
Both
Two technicians are discussing speaker testing methods. Technician A says that an 8 Ohm reading on a speaker is normal. Technician B says that you can quickly test a speaker using a AA battery. Who is right?
Both
Two technicians are discussing the proper use of an inductive current clamp. Technician A says to snap the jaws of the clamp to dissipate any storedmagnetic charge. Technician B says to "zero" the clamp before placing it around the wire to get aproper reading. Who is correct?
Both
The following statements are true EXCEPT: A. An oscilloscope screen is divided by horizontal and vertical lines called divisions. B. The trigger function can be used to capture a waveform when a specified condition occurs. C. The time scale settings of an oscilloscope have nothing to do with how the signal appears on the display. D. When setting up display screen of an oscilloscope, you must specify how many volts you want each division to represent.
C
The following statements are true EXCEPT: A. In a Controller Area Network (CAN), multiple ECUs are connected to a common communication bus, allowing each ECU to transmit or receive signals directly with any other ECU on the network. B. The CAN bus uses 120 ohm resistors at each end of the bus to stabilize voltages and prevent signals from bouncing back and corrupting communications. C. When the Can Main Bus has an open, communication is halted and the ECUs cease communication attempts. D. The 120 ohm terminating resistors may be located inside ECUs or inside junction connectors.
C
The following statements are true EXCEPT: A. The Controller Area Network (CAN) is limited to a maximum of 13 ECUs on a single network. B. The CAN bus uses 120 ohm resistors at each end of the bus to stabilize voltages and prevent signals from bouncing back and corrupting communications. C. When the CAN Main Bus has an open, communication is halted and the ECUs cease communication attempts. D. The 120 ohm terminating resistors may be located inside ECUs or inside junction connectors.
C
Coaxial cable is being discussed. Technician A says that the outer shielding is to isolate the inner conductor from interference. Technician B says that when testing coax, resistance between the center conductor and chassis ground should be below 4 Ohms. Who is correct?
tech A
What is the voltage of a LIN network while at rest?
12v
How long will the interior oscillators pulse if the door courtesy switch is cycled and the Engine/Power switch is not pressed?
30 seconds
Refer to the diagram below: The vehicle has been powered down and a resistance measurement across the disconnected skid control ECU. What is the expected approximate reading?
60 ohms
All of the following statements are true EXCEPT: A. Amplitude is a measure of the number of pulses for a waveform B. Hertz is a measure of frequency C. Duty cycle is expressed as the percentage of ON time D. Frequency is the number of times that a repeating waveform cycles per unit of time
A
All of the following statements related to smart start codes are correct, EXCEPT: A. The S Code is generated by the ID Code Box B. The 3-bit Code is a temporary immobilizer override which allows the engine to start quickly during G Code verification C. The G Code allows fuel and spark to the engine D. If G Code verification fails, the engine will crank, start, and stall and the security light will flash because the immobilizer is turned back ON
A
All the following statements are true EXCEPT: A. Amplitude is a measurement of the number of pulses for a waveform. B. Hertz is a measurement of frequency. C. Duty cycle is expressed as the percentage of ON time. D. Frequency is the number of times a repeating waveform cycles per unit of time.
A
Which of the following is correct? A. The tuner receives the Vehicle ID from the key via an RF signal and relays it to the Certification ECU via the RDA wire. B. When the tuner receives the Vehicle ID code from the key, it transmits a signal to the oscillator to command the doors to open. C. The Certification ECU uses the oscillator RF broadcast signals to command the key to transmit the Key ID Code. D. If the Vehicle ID Code does not match, the oscillator will pulse at a faster rate as long as the invalid key is in the detection area.
A
What causes the movement of a speaker's acoustical membrane?
AC current
Technician A says each unit of the navigation system connected to the AVC-LAN network will transfer switch signals using the AVC-LAN bus. Technician B says if a short to +B or short to ground occurs in the AVC-LAN, the navigation system will not function normally because communication is not possible. Who is correct?
Both
Which components must be functioning if the red light on the key flashes when approaching a locked vehicle?
An exterior (door) oscillator, Cert. ECU, Door lock control receiver/Tuner
All of the following statements related to the Smart Key System are correct, EXCEPT: A. If the key battery is below 2.5 V, the key cannot communicate with the vehicle. B. Cell phones and more than one key in the cabin during Key Registration can interfere with the registration process. C. If a continuous beep is heard when the key is held up to the power switch, it means that the key cannot be registered because it has been previously registered to another vehicle. D. If a key fails to register, check the FCC ID on the key and verify the FCC ID matches the other known good keys of the vehicle.
B
All of the following statements related to the Smart Key System are correct, EXCEPT: A. If the key battery is depleted and the Immobilizer Override Function does not work, it may indicate a problem with the key or the transponder coil in the power switch. B. If you suspect some sort of wireless device may be causing interference with the Smart Key System, the RF frequency of the device can be determined by accessing the FCC Website and entering the FCC ID. C. Some late model smart keys have a battery-saving function which prevents battery depletion by stopping the electronic key from transmitting or receiving radio waves. D. The Smart Key System can be disabled using the cancel function; the wireless door lock buzzer sounds once when smart key is canceled.
B
Technician A says for 2004 and early 2005 Prius, if the key remains in the detection area, the key battery will continuously draw. Technician B says when the key transmits the Key ID Code to the tuner, the red LED on the key flashes. Who is correct?
Both
Technician A says if a circuit is ON 75% of the time, it is operating at a 75% duty cycle. Technician B says when a circuit is duty-cycle controlled, the pulse frequency does not change, only the percentage of ON time compared to total cycle time. Who is correct?
Both
Technician A says during smart entry if the driver stays in the detection area, but does not attempt to enter the vehicle, the Main Body ECU will exit standby mode and re-arm the vehicle. Technician B says during smart entry when the driver opens the driver's door, the door courtesy switch turns ON and the door open warning light illuminates. Who is correct?
Both
A customer states that he is unable to control audio volume from the steering wheel controls. Technician A says that the spiral cable should be tested while rotated. Technician B says that the SRS system should be disabled before removing the spiral cable. Who is correct?
Both
A vehicle equipped with smart key has an intermittent no start condition. Technician A says defective stop light switch assembly could be the cause. Technician B says electromagnetic interference from an outside source could be the cause.
Both
AFS low speed swivel range is being discussed. Technician A says that during a right turn the left headlamp angle is fixed. Technician B says that during a left turn the left headlamp can swivel up to 15 degrees. Who is correct?
Both
Customer states that he can't hear the voice command and when using Bluetooth phone he can't hear the incoming caller but the caller can hear your customer. What could cause this?
Both
ECUs can be wired so they can detect the difference between an open or short and set a different DTC for each. Technician A says, in the throttle position sensor circuit shown below, a short-to-ground on a VTA line causes the monitored voltage to go to 0V. Technician B says, in the throttle position sensor circuit shown below, an open in the VTA line causes the monitored voltage to go to 5V. Who is correct?
Both
On models with a battery saving function, after 14 days, the door lock and unlock sensors are turned OFF. Technician A says these components are turned back on if the door is opened using the wireless remote. Technician B says these components are turned back on by using the mechanical key. Who is correct?
Both
Rear view monitor image quality is being discussed. Technician A says that high humidity could affect the quality of the image. Technician B says that fluorescent lighting could cause flickering of the image. Who is correct?
Both
Technician A says While the concepts of immobilizer components and operation are similar among all systems, the specifics of each system can vary significantly. Technician B says that for security reasons, immobilizer systems with a separate Transponder Key ECU are designed so that the vehicle will not start if either the ECM or ECU have been replaced. Who is correct?
Both
Technician A says a Hall Effect switch produces a DC voltage. Technician B says a Hall Effect switch produces a square waveform. Who is correct?
Both
Technician A says a network can be kept awake if one of the ECUs on the networks is receiving constant input from a faulty switch or sensor. Technician B says the Local Interconnect Network (LIN) has both sleep mode and the wake-up function, but the Audio Visual Communication-Local Area Network (AVC-LAN) does not. Who is correct?
Both
Technician A says a network can be kept awake if one of the ECUs on the networks is receiving constant input from a faulty switch or sensor. Technician B says the Local Interconnect Network (LIN) has both sleep mode and the wake-up function, but the Audio Visual Communication-Local Area Network (AVC-LAN) does not. Who is correct?
Both
Technician A says a permanent magnet sensor is constructed of a permanent magnet inside a coil of wire. Technician B says permanent magnet sensor produces an AC voltage. Who is correct?
Both
Technician A says a potentiometer is a voltage divider circuit used to measure movement of a component. Technician B says a magnetoresistive sensor alters current flow through the sense circuit when influenced by the magnetic field. Who is correct?
Both
Technician A says an open on a CAN main bus line affects the entire bus, but an open on a Branch Line only isolates the ECUs on that Branch Line. Technician B says when a vehicle has more than one CAN network, DLC3 is directly connected to only one of them, so by analyzing the ECUs that are communicating, you can determine which CAN network is experiencing trouble. Who is correct?
Both
Technician A says an open on a CAN main bus line affects the entire bus, but an open on a Branch Line only isolates the ECUs on that Branch Line. Technician B says when a vehicle has more than one CAN network, DLC3 is directly connected to only one of them, so by analyzing the ECUs that are communicating, you can determine which CAN network is experiencing trouble. Who is correct?
Both
To view the camera waveform, what terminals would you place the PicoScope leads across at the rear view camera connector? (See image below)
CV+ and CV-
A customer states there is no sound from the right front speaker. What should be checked first?
Check the balance and fade controls
The following statements are true EXCEPT: A. The "trigger" selection "rising or falling edge" specifies whether capture starts when the voltage signal crosses the threshold voltage while either rising or when falling. B. Threshold is the voltage level that a signal must cross to trigger a capture. C. To capture an intermittent fault, set the trigger to start capturing when the voltage goes out of range. D. The "trigger" function of an oscilloscope automatically resets the time and voltage settings.
D
Which of the following could cause image distortion of the rear view monitor? A. Nearby communication tower B. Use of electronic devices within the vehicle C. Damaged wire shielding D. All of the above
D
Which of the following statements is true? A. The ignition must be ON to connect to Smart Key Live in Techstream. B. If the key battery voltage is below 1.9V it is not possible to start the car. C. Smart Keys can be registered to more than one vehicle. D. Signal from the Stop Light switch must normally be received before the vehicle can be started.
D
If the signal being viewed on the Pico Scope is too small in amplitude you must:
Decrease the volt/division scale
What method of communication does AVC-LAN employ?
Differential voltage
Which of the following is not used for vehicle entry? Vehicle ID code, S code, Key ID Code, Cert. ECU
S code
What does the acronym: SDARS stand for?
Satellite Digital Audio Radio Service
What kind of obstacles disrupt the SDARS signal?
buildings, overpasses, tunnels, ect.
During MOST System Check Mode, what occurs if the CHEK icon is selected?
diagnostic trouble codes are displayed