Question 1

An air/fuel ratio sensor is different from an oxygen sensor in that ______.

Accepted Answer

A)  the signal output is a varying current (amps) 
B)  as the mixture becomes leaner, its output signal increases 
C)  the output responds to minor changes in air/fuel mixture, not just rich/lean conditions 
D)  all answers are correct 
A)  the signal output is a varying current (amps) 
B)  as the mixture becomes leaner, its output signal increases 
C)  the output responds to minor changes in air/fuel mixture, not just rich/lean conditions 
D)  all answers are correct D

Question 2

An accelerator pedal position sensor (APP) is used on vehicles equipped with ______.

Accepted Answer

A)  electronic throttle control 
B)  cruise control 
C)  torque converter clutch (TC
C)  
D)  all answers are correct 
A)  electronic throttle control 
B)  cruise control 
C)  torque converter clutch (TC
C)  
D)  all answers are correct A

Question 3

The ____________________ is the key sensor in the closed loop mode.

Accepted Answer

exhaust oxygen sensor
heated exhaust oxygen sensor
oxygen sensor
lambda sensor

Question 4

A sensor with a bad ground connection will produce a lower than normal signal voltage.

Accepted Answer

A) True 
 B)False

Question 5

How does the OBD-II catalytic converter efficiency monitor work?

Accepted Answer

All OBD-II vehicles have at least two ox

Question 6

Which of the following statements is NOT true?

Accepted Answer

A)  A conventional oxygen sensor has a minimum voltage of 0.000 volts and a maximum voltage of 1.000 volt. 
B)  On a V-type engine, bank 1 is the side of the engine where cylinder #1 is located. 
C)  An oxygen sensor measures the difference between the amount of oxygen inside the exhaust and the outside air. 
D)  A conventional oxygen sensor receives a 5-volt reference voltage from the PCM. 
A)  A conventional oxygen sensor has a minimum voltage of 0.000 volts and a maximum voltage of 1.000 volt. 
B)  On a V-type engine, bank 1 is the side of the engine where cylinder #1 is located. 
C)  An oxygen sensor measures the difference between the amount of oxygen inside the exhaust and the outside air. 
D)  A conventional oxygen sensor receives a 5-volt reference voltage from the PCM.

Question 7

Two technicians are discussing testing switch type sensors. Technician A uses an ohmmeter. Technician B uses a voltmeter. Who is correct?

Accepted Answer

A)  A only 
B)  B only 
C)  both A and B 
D)  neither A nor B 
A)  A only 
B)  B only 
C)  both A and B 
D)  neither A nor B

Question 8

Describe the driving procedure that will allow the OBD-II system to complete all monitors.

Accepted Answer

Engine must run continuously throughout

Question 9

Which of the following is NOT an actuator?

Accepted Answer

A)  PCV valve 
B)  fuel injector 
C)  canister purge solenoid 
D)  idle air control valve 
A)  PCV valve 
B)  fuel injector 
C)  canister purge solenoid 
D)  idle air control valve

Question 10

What is a waveform library?

Accepted Answer

A waveform library is a software package

Question 11

A MAP sensor with a varying frequency output can be tested with a(n) ______.

Accepted Answer

A)  voltmeter 
B)  ohmmeter 
C)  DMM with a duty cycle function 
D)  DMM with a frequency function 
A)  voltmeter 
B)  ohmmeter 
C)  DMM with a duty cycle function 
D)  DMM with a frequency function

Question 12

The PCM supplies a ____________________volt reference voltage to the MAP sensor.

Accepted Answer

The answer of The PCM supplies a ____________________volt reference voltage...

Question 13

What is a freeze-frame?

Accepted Answer

The PCM takes a snapshot of the activity

Question 14

Because air/fuel ratio sensors produce a signal only after their current output has been processed by the PCM, they cannot be tested with a voltmeter or lab scope.

Accepted Answer

A) True 
 B)False

Question 15

What is the OBD-II DLC and where is it located?

Accepted Answer

DLC stands for data link connector. The

Question 16

What is the cause of photochemical smog?

Accepted Answer

Photochemical smog is produced when hydr

Question 17

The resistance of the intake air temperature (IAT) sensor increases as air temperature increases.

Accepted Answer

A) True 
 B)False

Question 18

When the system is running rich, the oxygen content in the exhaust is ______.

Accepted Answer

A)  high 
B)  low 
C)  both A and B 
D)  neither A nor B 
A)  high 
B)  low 
C)  both A and B 
D)  neither A nor B

Question 19

The sensor and output status data stored when a DTC is set is called ______.

Accepted Answer

A)  snap shot data 
B)  freeze frame data 
C)  mode 6 data 
D)  failure record 
A)  snap shot data 
B)  freeze frame data 
C)  mode 6 data 
D)  failure record

Question 20

A bad sensor ground can allow ____________________ to interfere with the signals sent to the PCM, possibly causing drivability problems.

Accepted Answer

noise
line noise
EMI

Exam 25: Detailed Diagnosis and Sensors

An air/fuel ratio sensor is different from an oxygen sensor in that ______.

An accelerator pedal position sensor (APP) is used on vehicles equipped with ______.

The ____________________ is the key sensor in the closed loop mode.

A sensor with a bad ground connection will produce a lower than normal signal voltage.

How does the OBD-II catalytic converter efficiency monitor work?

Which of the following statements is NOT true?

Two technicians are discussing testing switch type sensors. Technician A uses an ohmmeter. Technician B uses a voltmeter. Who is correct?

Describe the driving procedure that will allow the OBD-II system to complete all monitors.

Which of the following is NOT an actuator?

What is a waveform library?

A MAP sensor with a varying frequency output can be tested with a(n) ______.

The PCM supplies a ____________________volt reference voltage to the MAP sensor.

What is a freeze-frame?

Because air/fuel ratio sensors produce a signal only after their current output has been processed by the PCM, they cannot be tested with a voltmeter or lab scope.

What is the OBD-II DLC and where is it located?

What is the cause of photochemical smog?

The resistance of the intake air temperature (IAT) sensor increases as air temperature increases.

When the system is running rich, the oxygen content in the exhaust is ______.

The sensor and output status data stored when a DTC is set is called ______.

A bad sensor ground can allow ____________________ to interfere with the signals sent to the PCM, possibly causing drivability problems.

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