Question 1

Which of the following problems would NOT cause a oxygen sensor to appear bad?

Accepted Answer

A) leaking fuel injector 
B) leaking intake manifold gasket 
C) leaking EGR valve 
D) leaking muffler to tailpipe gasket 
A) leaking fuel injector 
B) leaking intake manifold gasket 
C) leaking EGR valve 
D) leaking muffler to tailpipe gasket D

Question 2

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

Accepted Answer

DLC stands for data link connector. The DLC is a sixteen-pin terminal used to connect a scan tool to the vehicles computer network. The DLC is located inside the passenger compartment within easy access from the driver's seat. Typically the DLC is under the dash near the steering column. The DLC cannot be hidden behind panels and must be accessible without tools.

Question 3

A(n)____________________ is an electromechanical device that converts an electrical current into mechanical action.

Accepted Answer

actuators

Question 4

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

Accepted Answer

exhaust oxygen senso

Question 5

Which of the following tools cannot be used to test an oxygen sensor?

Accepted Answer

A) digital voltmeter (DMM) 
B) analog voltmeter 
C) lab scope 
D) scan tool 
A) digital voltmeter (DMM) 
B) analog voltmeter 
C) lab scope 
D) scan tool

Question 6

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 7

A misfiring spark plug can cause a false oxygen sensor reading.

Accepted Answer

A) True 
 B)False

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

Which of the following tools is NOT used in testing engine sensors?

Accepted Answer

A) DMM 
B) test light 
C) scan tool 
D) lab scope 
A) DMM 
B) test light 
C) scan tool 
D) lab scope

Question 10

The ____________________ sensor measures changes in intake manifold pressure that result from changes in engine load and speed.

Accepted Answer

The answer of The ____________________ sensor measures changes in intake...

Question 11

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

Accepted Answer

All OBD-II vehicles have at least two ox

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

The BARO sensor informs the PCM about changes in weather and ____________________.

Accepted Answer

The answer of The BARO sensor informs the PCM about...

Question 14

A typical upstream oxygen sensor should have a voltage that toggles between ____________________ volt (low)and ____________________ volt (high)when the system is working in closed loop.

Accepted Answer

The answer of A typical upstream oxygen sensor should have...

Question 15

A camshaft position sensor provides the PCM with data needed to control _____.

Accepted Answer

A) fuel injector timing 
B) variable valve timing 
C) ignition coil timing (COP ignition) 
D) All the answers are correct. 
A) fuel injector timing 
B) variable valve timing 
C) ignition coil timing (COP ignition) 
D) All the answers are correct.

Question 16

What is the primary function of an onboard diagnostic [OBD] system?

Accepted Answer

The primary goal of OBD system

Question 17

A vehicle towed into the shop will crank but won't start. A quick check under the hood reveals that the spark plugs are not firing and the injectors are not receiving a pulse from the PCM. The technician notices that the MIL light does not come on when the key is turned to the run position. What should he do next?

Accepted Answer

A) Check the PCM's fuses, power wires, and ground wires 
B) Replace the PCM 
C) Check the main power relay in the power distribution center 
D) Check for codes with a scan tool 
A) Check the PCM's fuses, power wires, and ground wires 
B) Replace the PCM 
C) Check the main power relay in the power distribution center 
D) Check for codes with a scan tool

Question 18

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

Question 19

What is a waveform library?

Accepted Answer

A waveform library is a software package

Question 20

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

Exam 25: Detailed Diagnosis and Sensors

Which of the following problems would NOT cause a oxygen sensor to appear bad?

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

A(n)____________________ is an electromechanical device that converts an electrical current into mechanical action.

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

Which of the following tools cannot be used to test an oxygen sensor?

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.

A misfiring spark plug can cause a false oxygen sensor reading.

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

Which of the following tools is NOT used in testing engine sensors?

The ____________________ sensor measures changes in intake manifold pressure that result from changes in engine load and speed.

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

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

The BARO sensor informs the PCM about changes in weather and ____________________.

A typical upstream oxygen sensor should have a voltage that toggles between ____________________ volt (low)and ____________________ volt (high)when the system is working in closed loop.

A camshaft position sensor provides the PCM with data needed to control _____.

What is the primary function of an onboard diagnostic [OBD] system?

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

What is a waveform library?

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

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A typical upstream oxygen sensor should have a voltage that toggles between volt (low)and volt (high)when the system is working in closed loop.