Question 1

A digital multimeter (DMM) is the instrument used to measure electricity in electronic circuits. A(n) ____________________ must be used to perform tests on these systems.

Accepted Answer

high-impedance voltmeter
high impedance voltmeter

Question 2

A scan tool is a portable computer that reads data from the on-board computer.

Accepted Answer

A scan tool is indeed a portable computer that is designed to read data from the on-board computer of a vehicle.

Question 3

All of the following statements are true EXCEPT:

Accepted Answer

An EGR valve is closed at idle during normal operation.

Question 4

While having a discussion, Technician A says that an ohmmeter should be used to test an O₂ sensor. Technician B says that you should not use an ohmmeter to test an O₂ sensor. Who is correct?

Accepted Answer

An O₂ sensor is a temperature sensor that uses resistance to determine temperature. Ohmmeters apply a small amount of voltage to measure resistance, but doing so could potentially damage the sensor or provide inaccurate readings. Therefore, an ohmmeter should not be used to test an O₂ sensor.

Question 5

Which of the following is LEAST-Likely an actuator?

Accepted Answer

Solenoids, fuel injectors, and stepper motors are all commonly used as actuators in various systems. However, an armature is typically a component of an electric motor and not used as a standalone actuator.

Question 6

The part MOST-Likely used to compare the reading inside the engine to an absolute pressure calibration in the computer is the:

Accepted Answer

The MAP sensor (Manifold Absolute Pressure sensor) is the part that measures the pressure inside the engine's intake manifold and sends the information to the computer. This information is then used to calculate the engine load and adjust the fuel delivery and ignition timing accordingly. In order to ensure accuracy, the computer needs to compare the reading from the MAP sensor to an absolute pressure calibration, which is typically provided by a BARO (Barometric Pressure) sensor. However, since the question only asks for the part most likely used for this purpose, the answer is still A – MAP sensor.

Question 7

A defective or misadjusted TPS can send an excessive voltage to the computer that is interpreted as ____.

Accepted Answer

An excessive voltage sent by a defective or misadjusted TPS is interpreted by the computer as Wide Open Throttle (WOT).

Question 8

While having a discussion, Technician A says that adaptive memory learns faster if the computer's memory is erased first. Technician B says that if memory is erased, it will take longer for the system to adapt. Who is correct?

Accepted Answer

The answer of While having a discussion, Technician A says...

Question 9

Active sensors do not generate their own signal.

Accepted Answer

Active sensors generate their own signal, while passive sensors detect and measure signals already present in the environment.

Question 10

To check a meter to see if it has high impedance, turn the selector to the direct current (DC) volts position.

Accepted Answer

When the selector is turned to the DC volts position, the meter's resistance will be in series with the circuit being measured, which will only allow a small amount of current to flow. A high impedance meter will have a very high resistance and will not draw much current from the circuit, indicating that it has high impedance.

Question 11

A(n) ____________________ in the service library provides a step-by-step diagnostic procedure to follow when troubleshooting hard-fault problems

Accepted Answer

The answer of A(n) ____________________ in the service library provides...

Question 12

The sensor that is MOST-Likely a low authority sensor is:

Accepted Answer

The intake air temperature sensor is considered a low authority sensor because it typically has a less direct or immediate impact on engine control compared to sensors like the oxygen sensor, mass airflow sensor, or throttle position sensor. It provides temperature data that can affect fuel mixture adjustments, but these adjustments are generally less critical for immediate engine performance.

Question 13

Bidirectional means that the scan tool can read data but cannot give commands to the computer.

Accepted Answer

Bidirectional means the scan tool can both read data from and send commands to the vehicle's computer, allowing for active testing and control of the vehicle's systems.

Question 14

Which of the following is LEAST-Likely a criteria found on the scan tool?

Accepted Answer

Forward bias is not a criteria that would typically be found on a scan tool. It is a term used in electronics to refer to the direction of current flow through a semiconductor device. The other choices (engine rpm, warm-up status, vehicle speed) are all parameters that can be monitored and diagnosed using a scan tool.

Question 15

An oscilloscope capable of displaying four waveforms is called a ____.

Accepted Answer

A four-channel oscilloscope can display four waveforms simultaneously, making it useful for analyzing complex signals or multiple signals in a system. The other answer choices (B, C, and D) are not commonly used or recognized terms in the field of oscilloscopes.

Question 16

If the charging system voltage is hovering near 11.6 volts, stepping on the brakes will turn on the brake lights, dropping the voltage further and causing the computer to raise engine idle.

Accepted Answer

When the charging system voltage is low and dropping further due to brake light activation, the engine computer may increase the idle speed to compensate for the increased electrical load.

Question 17

All of the following statements are true EXCEPT:

Accepted Answer

Load sensors typically include the MAP sensor and TPS, but not vacuum sensors.

Question 18

An ECT sensor is a thermistor; it will have lower resistance as coolant temperature rises. This is called a(n) ____________________ thermistor.

Accepted Answer

The answer of An ECT sensor is a thermistor; it...

Question 19

OBD II scan tools are powered through the ____________________ and do not require an external power source.

Accepted Answer

The answer of OBD II scan tools are powered through...

Question 20

To check a meter to see if it has high impedance, turn the selector to the ____________________ volts position.

Accepted Answer

The answer of To check a meter to see if...

Quiz 46: Electronics and Computer Systems Service

A digital multimeter (DMM) is the instrument used to measure electricity in electronic circuits. A(n) ____________________ must be used to perform tests on these systems.

A scan tool is a portable computer that reads data from the on-board computer.

All of the following statements are true EXCEPT:

While having a discussion, Technician A says that an ohmmeter should be used to test an O2 sensor. Technician B says that you should not use an ohmmeter to test an O2 sensor. Who is correct?

Which of the following is LEAST-Likely an actuator?

The part MOST-Likely used to compare the reading inside the engine to an absolute pressure calibration in the computer is the:

A defective or misadjusted TPS can send an excessive voltage to the computer that is interpreted as ____.

While having a discussion, Technician A says that adaptive memory learns faster if the computer's memory is erased first. Technician B says that if memory is erased, it will take longer for the system to adapt. Who is correct?

Active sensors do not generate their own signal.

To check a meter to see if it has high impedance, turn the selector to the direct current (DC) volts position.

A(n) ____________________ in the service library provides a step-by-step diagnostic procedure to follow when troubleshooting hard-fault problems

The sensor that is MOST-Likely a low authority sensor is:

Bidirectional means that the scan tool can read data but cannot give commands to the computer.

Which of the following is LEAST-Likely a criteria found on the scan tool?

An oscilloscope capable of displaying four waveforms is called a ____.

If the charging system voltage is hovering near 11.6 volts, stepping on the brakes will turn on the brake lights, dropping the voltage further and causing the computer to raise engine idle.

All of the following statements are true EXCEPT:

An ECT sensor is a thermistor; it will have lower resistance as coolant temperature rises. This is called a(n) ____________________ thermistor.

OBD II scan tools are powered through the ____________________ and do not require an external power source.

To check a meter to see if it has high impedance, turn the selector to the ____________________ volts position.

While having a discussion, Technician A says that an ohmmeter should be used to test an O₂ sensor. Technician B says that you should not use an ohmmeter to test an O₂ sensor. Who is correct?