Deck 9: Computer Inputssensor Diagnostic Routines

Question 1

Technician A says the phototransistor uses the application of light to generate  carriers to supply the base leg current. Technician B says photoelectric sensors use light-sensitive elements to detect rotation. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Answer 1

C

Question 2

The capacitance discharge sensor changes its capacitance by the difference in voltage between the electrodes.

Answer 2

False

Question 3

Intermittent faults with sensors usually set a(n) ____.

A) environmental data record
B) freeze frame
C) diagnostic trouble code (DTC)
D) All of the above

Answer 3

D

Question 4

The resistive multiplex switch is used to provide multiple inputs from a single switch using one sense circuit.

Question 5

A low voltage on the pressure sensor's supply circuit could be caused by any of the following except :

A) An open in the supply circuit wire.
B) A short to ground in the supply circuit wire.
C) High internal resistance in the sensor.
D) Excessive voltage drop in the supply circuit.

Question 6

Technician A says the output of one computer can also be used as an input to another computer. Technician B says a sensor is an output device. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 7

The pull-up resistor assures the proper high voltage reading by connecting the voltage sense circuit to an electrical potential that can be removed when the switch is closed.

Question 8

The piezoelectric accelerometer generates an analog voltage proportional to vehicle speed.

Question 9

Technician A says the output of a Hall-effect sensor can be checked with an AC voltmeter. Technician B says output of a magnetic pulse generator can be tested with a lab scope. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 10

What is the Wheatstone bridge used to measure?

A) Movement
B) Mechanical strain
C) Temperature
D) All of the above

Question 11

Feedback signals are used to confirm position and operation of an actuator.

Question 12

A Hall-effect switch operate on the principle that if a current is allowed to flow through a thin conducting material exposed to a magnetic field, another voltage is produced. A magnetic pulse generator uses electromagnetic induction to produce a voltage signal.

Question 13

A magnetic pulse generator uses electromagnetic induction to produce a voltage signal.

Question 14

____ means allowing the vehicle to sit without the engine running long enough that the coolant temperature equalizes with ambient temperature.

A) Ramping
B) Freezing
C) Cold soak
D) Ambient time

Question 15

Switches are computer output devices.

Question 16

Which of the following is an example of a piezoelectric sensor?

A) Oil pressure gauge sender unit
B) Knock sensor
C) Wheel speed sensor
D) Coolant temperature sensor

Question 17

Which of the following would NOT be considered a computer input?

A) Throttle position sensor
B) Magnetic pulse generator
C) Park/Neutral switch
D) EGR vent solenoid

Question 18

Magnetoresistive (MR) sensors consist of the magnetoresistive sensor element, a permanent magnet, and an integrated signal conditioning circuit to change resistance due to the relationship of the tone wheel and magnetic field surrounding the sensor.

Question 19

A Park/Neutral switch is being tested. When the transmission is placed in the park position, the voltage at the switch is 12 volts. When the transmission is shifted into reverse, the voltage drops to 0.0 volts. Technician A says the Park/Neutral switch needs to be replaced. Technician B says the ground circuit for Park/Neutral switch is open. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 20

Linear or rotary movement can be measured by a potentiometer.

Question 21

____ induction sensors use the principle of inducing a voltage into a winding by use of a moving magnetic field.

A) Electromechanical
B) Potential
C) Fluctuating
D) Magnetic

Question 22

The best way to test the performance of Hall-effect inputs is to use a(n) ____.

A) ammeter
B) DMM
C) voltmeter
D) lab scope

Question 23

A ____ is a series-parallel arrangement of resistors between an input terminal and ground.

A) potentiometer
B) piezoelectric device
C) Wheatstone bridge
D) Hall-effect sensor

Question 24

When inspecting magnetoresistive sensors, all of the following must be checked EXCEPT:

A) Bias voltage
B) Proper contact between the sensor and the tone wheel
C) Proper mounting of the sensor
D) Tone wheel teeth condition

Question 25

A thermistor is a solid-state ____ made from a semiconductor material that changes resistance as a function of temperature.

A) transducer
B) voltage regulator
C) conductor
D) variable resistor

Question 26

A photo cell describes any component that is capable of measuring or determining ____.

A) motion
B) heat
C) light
D) temperature

Question 27

Pressure switch circuits are ____ type switches.

A) transducer
B) simple on-off
C) sensor
D) actuator

Question 28

The _______________ resistor assures the proper low-voltage reading by preventing float when the switch is open.

A) pull-up
B) transducer
C) pull-down
D) variable

Question 29

A high voltage on the three-wire potentiometer sensor's signal circuit would most likely be caused by which of the following?

A) An open in the supply circuit.
B) An open in the signal circuit.
C) A short to ground in the supply circuit.
D) A short to ground in the signal circuit.

Question 30

Piezoelectric devices are used to measure ____ by the generation of voltage.

A) voltage drop
B) pressures
C) discharge rate
D) temperature

Question 31

It is becoming more common for manufacturers to use a(n) ____ temperature sensor instead of in-vehicle temperature sensors.

A) analog
B) surface
C) infrared
D) digital

Question 32

____ occurs when the switch is open resulting in the input to the voltage-sensing circuit of the control module being susceptible to electrical noise that may cause the control module to misread the switch state.

A) Pull-up circuiting
B) Pull-down circuiting
C) Floating
D) Multiplex switching

Question 33

Most motion and speed sensors use a(n) ____ as the sensing element or sensed target to detect rotational or linear speed.

A) magnet
B) photo cell
C) accelerometer
D) ammeter

Question 34

A piezoresistive sensor changes in ____ value as the pressure applied to the sensing material changes.

A) capacitance
B) conduction
C) resistance
D) photoconductive

Question 35

One form of feedback is for the computer to monitor ____ as a switch, relay, or other actuator is activated.

A) voltage
B) resistance
C) capacitors
D) gauges

Question 36

Pressure switches will usually use a(n) ____ that works against a calibrated spring or other form of tension.

A) diaphragm
B) electromagnet
C) lever
D) piezoelectrical device

Question 37

Instead of using a silicon diaphragm, the capacitance discharge sensor uses a ___________ capacitor.

A) transistorized
B) variable
C) photovoltaic
D) resistive

Question 38

By monitoring the thermistor's resistance value, the computer is capable of observing very small changes in ____.

A) current
B) temperature
C) gas
D) voltage

Question 39

A potentiometer sensor can be used to measure linear or ____ movement.

A) rotary
B) stationary
C) feedback
D) roll-over

Question 40

____ refers to the sensor signal being as constantly proportional to the measured value as possible.

A) Repeatability
B) Accuracy
C) Operating range
D) Linearity

Question 41

What is the principle of operation of the infrared temperature sensor?

Question 42

What type of temperature coefficient thermistors decrease their resistance as the temperature increases?

Question 43

Explain the difference in photovoltaic and photoconductive modes as they relate to photodiodes.

Question 44

Accelerometers can also be designed as piezoresistive sensors. What is the basic operating characteristics of this sensor?

Question 45

What converts some measurement of vehicle operation into an electrical signal?

Question 46

What type of switches operate on the principle that if a current is allowed to flow through thin conducting material exposed to a magnetic field, a voltage is produced?

Question 47

Describe the operation of the magnetoresistive (MR) sensor.

Question 48

Technician A says a pressure switch is used to monitor precise pressures. Technician B says if voltage is not present to the oil pressure switch with the ignition in the RUN position, the warning lamp bulb may be burned out. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 49

Explain the operation of the magnetically coupled linear sensor.

Question 50

Explain the purpose of the thermistor and how it is used in a circuit.

Question 51

Magnetoresistive can be used in which systems?

A) Antilock brake
B) Navigational
C) Lane change detection
D) All of the above

Question 52

How many wires does the linear Hall-effect sensor typically use?

Question 53

What does the potentiometric pressure sensor use to move the wiper arm on a resistive element?

Question 54

A capacitance discharge sensor that produces a digital voltage signal of varying frequency is being discussed. Technician A says a voltmeter can be used to monitor the signal circuit output. Technician B says a DMM that has a frequency measurement function can be used to monitor the signal circuit output. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 55

What type of input device uses the principle of magnetic induction to produce an AC voltage signal?

Question 56

Magnetically coupled linear sensors used for fuel level sensing are being discussed. Technician A says a magnet is attached to the float arm and when the magnetic field passes the comb, the fingers are pulled against the resistor card contacting resistors that represent the various levels of fuel. Technician B says different contact sites on the strip produce different resistances that are used to determine the fuel level. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 57

Technician A says an accelerometer may be mass-type, roller-type, or solid-state. Technician B says when a photodiode is in the photo conductive mode, it is reverse biased when no light is applied. Who is correct?

A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question 58

Describe the operation of the phototransistor.

Question 59

Why are dual-range temperature sensor circuits used?

Question 60

Describe how a capacitance discharge sensor that produces a digital frequency output can be diagnosed.