Deck 3: Common Components for Computerized Engine Control Systems

Question 1

How will an increase in temperature from 50^oF to 220 ^oF affect the resistance of an NTC thermistor?

A)The resistance decreases
B)The resistance increases
C)The resistance will be unaffected
D)The resistance should go to "infinity"

Answer 1

A

Question 2

Which of the following sensors cannot produce or generate a voltage signal?

A)Zirconium dioxide oxygen sensor
B)Permanent magnet sensor
C)Piezoelectric sensor
D)Potentiometer

Answer 2

D

Question 3

What type of signal does a Hall effect switch send to the PCM?

A)A digital DC voltage
B)A digital AC voltage
C)An analog DC voltage
D)An analog AC voltage

Answer 3

A

Question 4

What voltage will be produced by a zirconium dioxide O₂ sensor when the air-fuel ratio is on the rich side of stoichiometric?

A)0 mV
B)100 mV to 450 mV
C)450 mV
D)450 mV to 900 mV

Question 5

Which of the following types of sensors cannot be used as a RPM reference sensor?

A)Potentiometer
B)Permanent magnet
C)Optical
D)Hall Effect

Question 6

What type of sensor is a throttle position sensor?

A)Potentiometer
B)NTC thermistor
C)Piezoelectric diaphragm
D)Piezoresistive diaphragm

Question 7

Which of the following best describes how a permanent magnet sensor operates?

A)It modifies a reference voltage signal
B)It generates a DC analog voltage signal
C)It generates a DC digital voltage signal
D)It generates an AC voltage signal

Question 8

Which of the following sensors may be used in place of the "speed density formula"?

A)MAP sensor
B)VAF meter
C)MAF sensor
D)DPFE sensor

Question 9

Most often, how does the PCM energize an output actuator?

A)It supplies 5 volts to the actuator
B)It supplies battery voltage to the actuator
C)It supplies secondary ignition voltage to the actuator
D)It completes the actuator's ground path

Question 10

On a fuel injected engine, what is the most probable result of a faulty (worn)TPS that results in a voltage drop-out as the throttle is opened?

A)Cranks but won't start
B)Hesitates on acceleration
C)Starter cranks slow
D)Engine diesels on shutdown

Question 11

Technician A says that if a relay is normally open, it must be energized in order to complete the controlled circuit. Technician B says that if a solenoid-operated valve is normally closed, it must be energized in order to allow flow through it.Who is correct?

A)Technician A only
B)Technician B only
C)Both technicians
D)Neither technician

Question 12

If the vacuum hose to a MAP sensor were to rupture, what would the likely result be?

A)The engine would continue to run well because the O₂ sensor is the primary sensor
B)The PCM would go into open loop and run the engine excessively lean
C)The PCM would go into open loop and run the engine excessively rich
D)The PCM would see this sensor as being out of normal operating limits

Question 13

What scale on a DVOM should be used to test a zirconium dioxide O₂ sensor's signal?

A)An AC voltage scale
B)A DC voltage scale
C)A resistance scale
D)A diode test scale

Question 14

Technician A says that a switch in a "pull-up circuit" provides voltage to the computer when it is closed. Technician B says that a switch in a "pull-down circuit" provides a ground to the computer when it is closed. Who is correct?

A)Technician A only
B)Technician B only
C)Both technicians
D)Neither technician

Question 15

What is the "speed density formula" used to determine?

A)How much air is entering the engine
B)How much fuel is entering the engine
C)How much exhaust back pressure is present
D)How much CO and HC is being produced during combustion

Question 16

In the figure above, if there was an open at terminal "C", what would the voltage signal to the PCM be?

A)0 volts
B)About 1½ volts
C)About 3½ volts
D)5 volts

Question 17

In the figure above, as the engine coolant temperature sensor's resistance decreases, how will the voltage signal to the computer change?

A)The voltage signal decreases
B)The voltage signal increases
C)The voltage signal is unaffected
D)The sensor begins producing a digital frequency

Question 18

A digital Hall effect sensor consists of all of the following EXCEPT :

A)a shutter wheel with vanes and windows
B)a permanent magnet
C)a Hall effect crystal
D)a light emitting diode

Question 19

Two technicians are discussing how to test a permanent magnet vehicle speed sensor. Technician A says that you should test the coil's resistance and compare it to specification. Technician B says that you should set your DVOM to the " DC volts " scale to test the sensor's ability to produce voltage. Who is correct?

A)Technician A only
B)Technician B only
C)Both technicians
D)Neither technician

Question 20

All of the following sensors vary resistance so as to modify a voltage signal EXCEPT :

A)Potentiometer
B)NTC Thermistor
C)Zirconium dioxide oxygen sensor
D)Piezoresistive diaphragm