Question 1

In heating mode, where is the airflow directed?

Accepted Answer

In heating mode, the airflow is typically directed towards the floor and the windshield. This helps in warming the vehicle's interior and defrosting the windshield for clear visibility.

Question 2

Which sensor is also called the ambient air temperature sensor?

Accepted Answer

The outside air temperature sensor, also known as the ambient air temperature sensor, measures the temperature of the air outside the vehicle to help manage the car's heating, ventilation, and air conditioning (HVAC) system.

Question 3

What is the most common type of sunload sensor?

Accepted Answer

The most common type of sunload sensor is a photo diode, which is used to detect sunlight intensity. This is because photo diodes are sensitive to light and can generate an electrical signal proportional to the light intensity, making them ideal for sunload sensing applications in automotive and building automation systems.

Question 4

An actuator can be capable of how many positions?

Accepted Answer

Actuators can be designed to achieve various positions, including two positions (on/off), three positions, or variable positions, depending on the control requirements and the design of the system.

Question 5

Some cabin filters contain ________ to absorb odors

Accepted Answer

Activated charcoal is used in some cabin filters to absorb odors, thanks to its porous nature and large surface area, which makes it effective at trapping odor-causing particles and gases.

Question 6

Which sensor might use an aspirator tube?

Accepted Answer

An aspirator tube is often used with the inside vehicle temperature sensor to draw cabin air over the sensor for more accurate readings.

Question 7

Technician A says that some cabin filters are accessible behind the glove compartment. Technician B says that some cabin filters are accessible from under the hood. Which technician is correct?

Accepted Answer

Both technicians are correct because cabin air filters can indeed be located in different places depending on the vehicle's design. Some are accessible behind the glove compartment, while others can be accessed from under the hood.

Question 8

The blower motor resistors are used to limit ________ to the motor

Accepted Answer

Blower motor resistors are used to control the speed of the blower motor by limiting both the current and voltage to the motor, allowing for variable fan speeds.

Question 9

Which is NOT part of a rear air conditioning system?

Accepted Answer

The rear AC compressor is not part of a rear air conditioning system because there is typically only one AC compressor in a vehicle, located in the engine compartment, that serves both the front and rear AC systems.

Question 10

What components in the AC system may be different on a hybrid electric vehicle?

Accepted Answer

The compressor in a hybrid electric vehicle is often electrically driven to allow for cooling when the engine is off, unlike traditional vehicles where the compressor is typically belt-driven by the engine.

Question 11

Which of these is an example of a three-position actuator?

Accepted Answer

The answer of Which of these is an example of...

Question 12

Where is the ambient temperature sensor usually mounted?

Accepted Answer

The ambient temperature sensor is typically mounted in front of the radiator or near the front bumper to accurately measure the outside air temperature, which can affect the vehicle's climate control system and engine performance.

Question 13

Which of the following is NOT a component of an automatic temperature control system?

Accepted Answer

All the options listed (A, B, C) are indeed components of an automatic temperature control system, making D incorrect as it suggests they are not.

Question 14

Technician A says that the HVAC doors in an automatic system may be vacuum operated. Technician B says that the HVAC doors in an automatic system may be operated by electric servos. Which technician is correct?

Accepted Answer

Both vacuum-operated and electric servo-operated mechanisms are used in automatic HVAC systems to control the movement of doors that direct airflow within the system.

Question 15

Which of the following is NOT a sensor in an ATC system?

Accepted Answer

Humidity sensors are not typically used in Automatic Temperature Control (ATC) systems for vehicles. ATC systems primarily rely on sensors that measure temperature (such as in-car temperature sensors, ambient air temperature sensors) and sunlight intensity (sun load sensors) to adjust the vehicle's internal environment.

Question 16

Which component is used as a feedback circuit?

Accepted Answer

A potentiometer is often used as a feedback circuit to provide variable resistance, allowing for adjustments in electronic circuits.

Question 17

Which of these ATC output devices provides a feedback signal to the electronic control module (ECM)?

Accepted Answer

The blend door actuator is an ATC output device that provides a feedback signal to the electronic control module (ECM) to indicate the position of the blend door, which controls the mixing of hot and cold air in the vehicle's HVAC system.

Question 18

Which of the following is TRUE regarding the cabin air filter?

Accepted Answer

Both statements A and B are correct regarding the cabin air filter. A) Filter restrictions can indeed reduce the volume of air entering the passenger compartment, affecting HVAC system performance and comfort. B) The cabin air filter is typically mounted in the incoming air stream from the cowl intake to filter air entering the HVAC system.

Question 19

An ATC system has the ability to automatically ________.

Accepted Answer

An ATC (Automatic Temperature Control) system can automatically adjust the blower speed, change the function door setting, and move the temperature-blend door to maintain the desired cabin temperature, hence all of these options are correct.

Question 20

The purpose of the afterblow system is to dry the evaporator to help prevent the formation of ________ in the evaporator case.

Accepted Answer

The afterblow system helps to dry the evaporator in air conditioning systems, preventing the formation of mold and mildew by removing moisture that could serve as a breeding ground for these organisms.

Quiz 63: Automatic Air-Conditioning System Operation