How does the automatic climate control system work?

How does the automatic climate control system work?
Experienced mechanics share their insights in answering this question :
If your vehicle includes an automatic climate control system (higher end trims only), you have the ability to “set it and forget it” when it comes to heating and cooling. Using the system is simple, too. Here’s what you need to know:

Press the button labeled “Auto.”
Set the temperature dial to your desired level.

The climate control system will automatically turn on the heat or air, and adjust fan speed to ensure that the interior of the cabin remains at your desired temperature level. However, you can adjust the direction of the airflow by turning the vents to a new position.

Tips

Both the driver and passenger side have independent temperature controls.
The SYNC button makes the driver and passenger side temperatures equal.
The On/Off button turns the climate control system on or off. When turning it on, it will resume with the last setting used.

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Using Automatic Climate Control

The automatic climate control system maintains the interior temperature you select. The system also selects the proper mix of heated or cooled air that raises or lowers the interior temperature to your preference as quickly as possible. Use the system when the engine is running.

Automatic Climate Control is an air conditioning system that maintains the manually pre-set interior temperature of your car at the desired level. It ensures you and your passengers feel comfortable, regardless of the weather conditions.
Climate control consistently monitors the temperature in the car and then heats or cools the cabin space accordingly, whereas air-con is more of a manual system where you have to tell it what to do. You set the temperature and fan speed, and then the air con will stay on those settings until you adjust them yourself.
Dual-zone climate control is a system that allows the vehicle`s front-seat passengers to set their own preferred temperature for their “zone,” or their area of the front cabin. It`s a smarter, more personalized version of basic automatic climate control systems that let you set a single temperature for the whole cabin.
The automatic climate control system provides an individual feel-good climate for the occupants. It automatically controls the temperature, air-flow and air distribution inside the cabin. The climate control system also controls the fan speed and air circulation.
There are five components that comprise an automotive climate control system – evaporator, compressor, condenser, receiver, Fluid Transport and then expansion device.
Yes, it does.

The AC powers itself using the engine which puts an extra load on the engine making it use more fuel. However, in a small speed frame, it will consume less fuel than running the car with windows down.

Tips for operating the air conditioning system

The ideal temperature is between 22 and 25 degrees.

There are two fundamental types of temperature control; open loop and closed loop control.
Automatic Temperature Control (ATC) systems require a complex array of internal and external sensors that include ambient air temperature sensors, interior temperature sensors, outlet duct and evaporator temperature sensors, pressure sensors, humidity sensors, blend door position sensors and sunload sensors.
There are benefits to having your air conditioner set to “auto” and “on.” The benefits of the “auto” setting include higher efficiency, lower energy bills, better humidity control, less wear and tear on some components, and quieter running.
Why you should normally set your thermostat to AUTO. Compared to the ON setting, the AUTO setting gives you benefits such as: Lower energy consumption. In AUTO mode, the blower fan only runs when necessary, which cuts down your AC system`s energy usage.
Eco Mode. The eco mode is one of the most energy-efficient modes on your air conditioner modes and functions. The eco mode works by efficiently using the AC unit`s compressor and fan so that minimal energy is consumed to achieve the desired temperature.
Idling uses up to ½ gallon of fuel per hour (although it varies depending on the type and size of the engine).
Yes, it does.

The AC powers itself using the engine which puts an extra load on the engine making it use more fuel. However, in a small speed frame, it will consume less fuel than running the car with windows down.

The turbo mode is the most powerful. It`s for absolute quick cooling. It allows users to cool a room quickly and effectively by operating at a span of 30 minutes before switching back to the previous settings.
Climate control is clearly the better system as it allows you the full manual control air-con does, but with far greater convenience. Dual, tri and quad-zone climate, meanwhile, are great if your partner or kids, for example, like a different temperature from you in the car. Balanced against this is cost, naturally.
Climate control is clearly the better system as it allows you the full manual control air-con does, but with far greater convenience. Dual, tri and quad-zone climate, meanwhile, are great if your partner or kids, for example, like a different temperature from you in the car. Balanced against this is cost, naturally.
If something inside a manual AC goes wrong, the most you`ll have to fix is a compressor or condenser. If the automatic climate control`s sensors and electronics go awry, be ready for hefty charges. It`s not a must-have feature.
If something inside a manual AC goes wrong, the most you`ll have to fix is a compressor or condenser. If the automatic climate control`s sensors and electronics go awry, be ready for hefty charges. It`s not a must-have feature.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

How does the automatic climate control system work?
ANSWER : If your vehicle includes an automatic climate control system (higher end trims only), you have the ability to “set it and forget it” when it comes to heating and cooling. Using the system is simple, too. Here’s what you need to know:

Press the button labeled “Auto.”
Set the temperature dial to your desired level.

The climate control system will automatically turn on the heat or air, and adjust fan speed to ensure that the interior of the cabin remains at your desired temperature level. However, you can adjust the direction of the airflow by turning the vents to a new position.

Tips

Both the driver and passenger side have independent temperature controls.
The SYNC button makes the driver and passenger side temperatures equal.
The On/Off button turns the climate control system on or off. When turning it on, it will resume with the last setting used.

Read Full Q/A … : How does the automatic climate control system work?

How does semi-automatic climate control work?
ANSWER : If your vehicle is equipped with automatic climate control, you can switch the system to semi-automatic operation if you want. This gives you more control over certain aspects of the system, but it means that it won’t be completely automatic. In semi-automatic mode, you can control:

Fan speed
Air conditioner operation
Recirculation/fresh air
Mode
Windshield defrost

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Does non-climate control car AC cut-in & cut-off automatically?
ANSWER : A/C systems that used fixed displacement compressors will cycle on and off (the compressor that is) depending on cooling demand. If you have a variable displacement compressor in your vehicle, though, the compressor may hardly ever cycle simply because the compressor is capable of load following. In fixed displacement systems, without automatic climate control, the rate of cycling is usually determined by pressures within the system. An example of this type of system is what’s known as a CCOT (cycling clutch orifice tube) system. The compressor clutch will cycle on and off depending on cooling demand, usually at around 21-23 psi on the suction side, but of course there is variance from car model to car model. On newer car, the vehicle’s PCM is involved in the control strategy, too, as the PCM can command the compressor off during periods of high engine demand, such as rapid acceleration. Insofar as climate control heating and HVAC systems, those are electronically controlled and, in the main, merely "automate" all the mechanical controls that formerly were used to control the position of blend doors and the heater control valve. Control strategies are electronics-based. If you need a diagnostic of a vehicle HVAC problem, performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request HVAC inspection/testing and the responding certified mechanic will address your issue(s). If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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How do you use Dual Zone Automatic Climate Control with the in-dash navigation system?
ANSWER : If you have a built-in navigation system and your car also has Dual Zone Automatic Climate Control, you’ll find that operating the system is a little bit different from either the manual climate control or the non-navigation based Dual Zone Automatic Climate Control platforms. Here’s what you need to know:

Climate: Press the Climate button on the navigation touchscreen to control the system.
Rear Defrost: This turns the rear defroster on and off.
A/C: This turns the air conditioner on.
Passenger Temp: This lets you set the temperature for the passenger side of the car (automatic climate control).
Heated Seats: You have two buttons for seat heaters, one for the driver and one for the front passenger. Press the appropriate button to turn on the seat heater in that seat. Press it again to turn it off.
Recirculation: This changes the system from fresh outside air to recirculated air.
Fan Speed: This changes the speed of the fan/blower.
Auto: Push this button to turn the Automatic Climate Control system from manual to automatic.
Driver Temp: This lets you set the temperature for the driver side of the car (automatic climate control).
Power: Push this button to turn the climate control system on or off. If the Power button is off, you cannot select Climate Control from the touchscreen.
Defrost: Turns on the front defroster, which is tied to the air conditioner.

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How does the automatic climate control system detect the temperature?
ANSWER : In order for the automatic climate control system to work, it needs to know the temperature inside, as well as the temperature/amount of sunlight entering the cabin. It gets this information from two sensors.

Sunlight Sensor: The sunlight sensor can be found on the dash of your car, close to the windshield.
Temperature Sensor: The temperature sensor is located on the dash, to the right of the steering column.

Tip

Both the sunlight sensor and the temperature sensor need to be unobstructed in order to operate correctly.

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Defrost button wont come on. Control power button doesnt work.
ANSWER : It seems like the defrost of the vehicle has an issue. There are several possibilities that could cause this. The control unit for the climate control system could be malfunctioning. The fuse for the rear defrost could be blown due to some unknown reason. The windshield itself could be damaged and lost connection somehow. I would recommend having a qualified professional who is proficcient in electrical diagnosis inspect your vehicle with a wiring diagram. This will help to determine where the fault in the defrost system is located. Once the issue is found, I would recommend having the issue resolved as soon as possible to prevent any safety issues that could result from lack of clear vision through the rear window.

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How do I turn on the defogging logic feature with the automatic climate control system?
ANSWER : The defogging logic feature automatically controls the air intake to keep the window from fogging up. To set the defogging logic system, follow these steps:
1. Turn the ignition to the ON position.
2. Press the Defrost button.
3. Press and hold the A/C button.
4. While holding the A/C button, press the Air Intake Control button five consecutive times. The indicator on the button will then flash three times to confirm the setting.
To turn off the defogging logic, repeat these steps.

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Climate control no mode function?
ANSWER : Hello, thanks for writing in. I’d be happy to help.

From what you describe it appears that your vehicle is experiencing some sort of electrical issue. It may be possible that the some sort of wiring problem has occurred, or that the components you replaced are defective. I would carefully inspect the vehicle for any wiring issues, though from what you describe, the unit operating in reverse, it is more likely that the component is defective. It is not uncommon for aftermarket components to be defective out of the box, so if you suspect the component may be defective, I would replace it. A wiring diagram can be sourced from either the dealership, or out of a quality service manual.

If you would like help inspecting the electrical components, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make any repairs as needed.

Read Full Q/A … : How does the automatic climate control system work?

Eric smoalih

I am a certified master technician with the National Institute for Automotive Service Excellence (ASE), and I have been working as an auto mechanic for over 15 years. I am passionate about my work, and I take great pride in helping people keep their cars running smoothly.