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 device used to interface with a vehicle's on-board computer system for the purpose of reading and diagnosing the data and codes it generates.

Question 3

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

Accepted Answer

Forward bias is a term more commonly associated with semiconductor devices, such as diodes, rather than a parameter typically monitored by automotive scan tools. Engine rpm, warm-up status, and vehicle speed are standard data points that scan tools can read from a vehicle's onboard diagnostics system.

Question 4

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

Accepted Answer

A defective or misadjusted Throttle Position Sensor (TPS) can send an excessive voltage signal to the computer, which might be interpreted as Wide Open Throttle (WOT). This is because the TPS indicates the position of the throttle to the engine control unit, and an excessive voltage could falsely indicate that the throttle is fully open.

Question 5

Active sensors do not generate their own signal.

Accepted Answer

Active sensors generate their own signal to measure properties or changes in the environment, unlike passive sensors that rely on external sources of energy.

Question 6

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 7

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 (Manifold Absolute Pressure) sensor is used to measure the pressure inside the intake manifold and compare it to an absolute pressure calibration in the computer. This helps in determining the air mass entering the engine for the correct fuel delivery.

Question 8

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 performance adjustments compared to sensors like the mass airflow sensor or throttle position sensor. It measures the temperature of the air entering the engine and slightly adjusts the air-fuel mixture based on this temperature, but its data does not drastically change engine operations in most situations.

Question 9

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 10

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 11

Which of the following is LEAST-Likely an actuator?

Accepted Answer

An armature is typically a component in electric motors or electrical generators, playing a crucial role in the electromagnetic process but not acting as an actuator itself. Actuators like solenoids, fuel injectors, and stepper motors directly convert energy into motion.

Question 12

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

Using an ohmmeter to test a sensor, especially one that might be sensitive to the current used in such tests, can damage the sensor. Sensors like the O₂ are often designed to operate within specific electrical parameters, and the introduction of external currents for testing purposes can lead to inaccurate results or damage.

Question 13

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 14

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

Accepted Answer

Turning the selector to the DC volts position allows you to check if the meter has high impedance because high-impedance voltmeters are designed to minimize their impact on the circuit being measured, and the DC volts setting is appropriate for this purpose.

Question 15

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...

Question 16

All of the following statements are true EXCEPT:

Accepted Answer

Load sensors typically include the MAP sensor and TPS, but not vacuum sensors. Vacuum is a condition measured by the MAP sensor, not a separate sensor itself.

Question 17

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

Accepted Answer

A four-channel scope refers to an oscilloscope that can simultaneously display four separate input signals, or waveforms, on its screen.

Question 18

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 (around 11.6 volts), turning on additional electrical loads such as the brake lights will further drop the voltage. The vehicle's computer detects this drop and compensates by increasing the engine idle speed to generate more power and stabilize the voltage.

Question 19

All of the following statements are true EXCEPT:

Accepted Answer

The EGR (Exhaust Gas Recirculation) valve is typically closed at idle and opens under certain driving conditions to allow exhaust gases back into the combustion chambers to reduce NOx emissions. If it were open at idle during normal operation, it could cause the engine to run poorly or stall.

Question 20

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.

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.

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

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

Active sensors do not generate their own signal.

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?

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

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

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

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

Which of the following is LEAST-Likely an actuator?

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?

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

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

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

All of the following statements are true EXCEPT:

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:

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

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?